Selenoproteins synergistically protect porcine skeletal muscle from oxidative damage via relieving mitochondrial dysfunction and endoplasmic reticulum stress

Background The skeletal muscle of pigs is vulnerable to oxidative damage,resulting in growth retardation.Selenoproteins are important components of antioxidant systems for animals,which are generally regulated by dietary selenium(Se)level.Here,we developed the dietary oxidative stress(DOS)-inducing pig model to investigate the protective effects of selenoproteins on DOS-induced skeletal muscle growth retardation.Results Dietary oxidative stress caused porcine skeletal muscle oxidative damage and growth retardation,which is accompanied by mitochondrial dysfunction,endoplasmic reticulum(ER)stress,and protein and lipid metabolism disorders.Supplementation with Se(0.3,0.6 or 0.9 mg Se/kg)in form of hydroxy selenomethionine(OH-SeMet)linearly increased muscular Se deposition and exhibited protective effects via regulating the expression of selenotranscriptome and key selenoproteins,which was mainly reflected in lower ROS levels and higher antioxidant capacity in skeletal muscle,and the mitigation of mitochondrial dysfunction and ER stress.What’s more,selenoproteins inhibited DOS induced protein and lipid degradation and improved protein and lipid biosynthesis via regulating AKT/mTOR/S6K1 and AMPK/SREBP-1 signalling pathways in skeletal muscle.However,several parameters such as the activity of GSH-Px and T-SOD,the protein abundance of JNK2,CLPP,SELENOS and SELENOF did not show dose-dependent changes.Notably,several key selenoproteins such as MSRB1,SELENOW,SELENOM,SELENON and SELENOS play the unique roles during this protection.Conclusions Increased expression of selenoproteins by dietary OH-SeMet could synergistically alleviate mitochondrial dysfunction and ER stress,recover protein and lipid biosynthesis,thus alleviate skeletal muscle growth retardation.Our study provides preventive measure for OS-dependent skeletal muscle retardation in livestock husbandry.

Two New Selenoproteins Found in the Prostatic Glandular Epithelium and in the Spermatid Nuclei

After labeling of rats in vivo with 75Se and protein separation by sodium dodecyl sulfatepolyacrylamide gel electrophoresis more than 25 Se-containing bands could be distinguished.Of those proteins which were detected only in certain compartments and might therefore have tissue-specific functions, two were chosen for detailed investigation.A 15 kDa-protein was found in the prostatic epithelium where it accounted for about two thirds of the protein-bound 75Se. It was mainly present in the cytosol but was not released into the prostatic secretion. After gel chromatography it was found in the fraction which contained proteins with molecular masses of about 300 kDa. Using two-dimensional electrophoresis a plvalue of about 4. 5 was determined.In the testis a specific Se-containing 34 kDa-protein was observed which appeared after the onset of puberty. It was localized in the spermatid nuclei where it contained about 80% of the Se tracer present and was found to be bound to the DNA. After extraction it partly disintegrated into a 20 kDa-protein.Both compounds contain Se in the form of selenocysteine. The fact that their formation had priority over that of glutathione peroxidase during insufficient Se intake is an indication of their biological significance. Special interest in the prostatic epithelial selenoprotein derives from a possible inverse relationship between the Se status and the incidence of prostate cancer observed in epidemiological studies, whereas with the 34 kDa-selenoprotein its appearance during the condensation phase of the spermatid nuclei might suggest its participation in some processes of sperm maturation

Maternal reproductive health: Expression patterns of antioxidant enzyme selenoproteins of post-implantation embryos conceived by ethanol-treated murine mothers supplemented with α-tocopherol

Objective:To investigate if the protective effect ofα-tocopherol against the impact of ethanol on brain morphogenesis involved the activity of the selenoproteins phospholipid hydroperoxide glutathione peroxidase (PHGPx;GPx4) and selenoprotein P (SelPP) that have roles against oxidative stress.Methods:Forty female mice were randomly assigned into natural control (CON), positive control (ETOH), low-, medium-, and high-α-tocopherol-supplemented-ethanol groups (LTOC, MTOC, HTOC, respectively). CON received drinking water without ethanol while ETOH, LTOC, MTOC and HTOC groups received 20% ethanol in drinking water. The supplemented groups were given respective dosages ofα-tocopherol, 0.410, 0.819, and 1.640 mg/g body weight, at day 14 before mating onwards to the day 9 of gestation. At 10.5 ED of gestation (1100 h), the pregnant females were sacrificed by cervical dislocation and the embryos were harvested. Total RNA were extracted, cDNA synthesis and qRT- PCR analyses were carried out.Results: The level of expression of PHGPx in the positive control was significantly lower than that of the natural control. Among the threeα-tocopherol-supplemented groups, only the medium dose- group was significantly higher than the positive control. The level of expression of SelPP in the positive control was significantly lower than those of the natural control, the low- and medium- dose -tocopherol supplemented groups. In the high dose-α-tocopherol supplemented group, the level of expression was not significantly different from the positive control but significantly lower than the natural control.Conclusions: The activity of the selenoproteins PHGPx and SelPP are involved in the internetwork of antioxidative enzymes with vitamin E when given up to a medium dose only and is one of the possible pathways of shielding embryonic development against the impact of ethanol on brain morphogenesis. This study strengthens the impact of dietaryα-tocopherol and Selenium supplement during the critical period of pregnancy.

Ebola viral selenoproteins:a metallomics analysis

Ebola virus infection is the present public health problem.The trend of worldwide epidemic becomes the serious consideration for this infection.The Ebola virus infection has main clinical manifestation as acute febrile illness with hemorrhagic episode.The problem of hemostatic disturbance can be seen.Focusing on the palhophysiology.selenium plays an important role in the blood clotting regulation.The study on the selenoprotein of the Ebola virus can be useful for further understanding on the pathology of the infection.Here,the authors use metallomics analysis for assessment of Ebola virus genome.According to this study,the selenoprotein portion within Ebola virus genome can be detected at position 1046-1115.

Identification of selenocyst-eine insertion sequence(SECIS) element in eukaryotic selenoproteins by RNA Draw program

The computer program RNA Draw was used to identify the secondary structures in the 3’untranslated regions (3’UTRs) of the mRNAs from 46 eukaryotic seleno-proteins among 7 species. The program found one or two possible SECIS elements in these selenoproteins. The SECIS element consists of a stem-loop or hairpin structure with three conserved sequences of AUGA-(A)AA-GA. SECIS element was not found by the RNA Draw program in randomly selected non-selenoproteins. The results showed that SECIS element is the unique character of the genes ofeukaryotic selenoproteins. Thus it is possible to use RNA Draw to search the SECIS elements in gene bank for potential new selenoproteins.

Determination of optimal dietary selenium levels by full expression of selenoproteins in various tissues of broilers from 1 to 21 d of age

The current NRC dietary selenium(Se)requirement(0.15 mg/kg)of broilers is primarily based on growth performance data reported in 1986.Our study aimed to determine optimal dietary Se levels of broilers fed a practical corn-soybean meal diet for the full expression of selenoproteins in various tissues.A total of 384 one-d-old male broilers(n=8 replicates/diet)were fed a basal corn-soybean meal diet or the basal diet supplemented with 0.1,0.2,0.3,0.4 or 0.5 mg Se/kg in the form of Na_(2)SeO_(3) for 21 d.Regression analysis was conducted to evaluate the optimal dietary Se levels using broken-line,quadratic or asymptotic models.The activity of glutathione peroxidase(GPX)in the plasma,liver,kidney and pancreas,iodothyronine deiodinase(DIO)in the plasma,liver and pancreas,and thioredoxin reductase(Txnrd)in the liver and pancreas,the mRNA levels of Gpx1,Gpx4,Dio1,selenoprotein(Seleno)h,Selenop and Selenou in the liver,Gpx4,Dio1,Txnrd1,Txnrd2,Selenoh,Selenop and Selenou in the kidney,and Gpx1,Gpx4,Selenoh and Selenou in the pancreas,and the protein levels of GPX4 in the liver and kidney of broilers were influenced(P<0.05)by added Se levels,and increased quadratically(P<0.05)with the increase of added Se levels.The estimates of optimal dietary Se levels were 0.07 to 0.36 mg/kg based on the fitted broken-line,quadratic or asymptotic models(P<0.001)of the aforementioned selenoprotein expression in the plasma,liver and kidney,and 0.09 to 0.46 mg/kg based on the fitted broken-line models(P<0.001)of the aforementioned selenoprotein expression in the pancreas.The results indicate that the optimal dietary Se levels would be 0.36 mg/kg to support the full expression of selenoproteins in the plasma,liver and kidney,and 0.46 mg/kg to support the full expression of selenoproteins in the pancreas of broilers fed a practical corn-soybean meal diet from 1 to 21 d of age.

New selenoproteins identified in silico from the genome of Anopheles gambiae

Selenoprotein is biosynthesized by the incorporation of selenocysteine into proteins,where the TGA codon in the open reading frame does not act as a stop signal but is translated into selenocysteine.The dual functions of TGA result in mis-annotation or lack of selenoproteins in the sequenced genomes of many species.Available computational tools fail to correctly predict selenoproteins.Thus,we devel-oped a new method to identify selenoproteins from the genome of Anopheles gambiae computationally.Based on released genomic information,several programs were edited with PERL language to identify selenocysteine insertion sequence(SECIS)element,the coding potential of TGA codons,and cys-teine-containing homologs of selenoprotein genes.Our results showed that 11365 genes were termi-nated with TGA codons,918 of which contained SECIS elements.Similarity search revealed that 58 genes contained Sec/Cys pairs and similar flanking regions around in-frame TGA codons.Finally,7 genes were found to fully meet requirements for selenoproteins,although they have not been anno-tated as selenoproteins in NCBI databases.Deduced from their basic properties,the newly found se-lenoproteins in the genome of Anopheles gambiae are possibly related to in vivo oxidation tolerance and protein regulation in order to interfere with anopheles' vectorial capacity of Plasmodium.This study may also provide theoretical bases for the prevention of malaria from anopheles transmission.

Determination of optimal dietary selenium levels by full expression of selenoproteins in various tissues of broilers from 22 to 42 d of age

The current NRC dietary selenium(Se)requirement(0.15 mg/kg)of broilers from 22 to 42 d of age is primarily based on a previous study reported in 1986,which might not be applicable to modern classes of rapidly growing broilers.The present experiment was conducted to determine the optimal dietary Se level for meeting metabolic and functional Se requirements of broilers fed a corn-soybean meal diet from 22 to 42 d of age.A total of 336 Arbor Acres male broilers at 22 d old were randomly assigned to 1 of 6 treatments with 7 replicates and fed a basal corn-soybean meal diet(control,containing 0.014 mg Se/kg)and the basal diet supplemented with 0.10,0.20,0.30,0.40,or 0.50 mg Se/kg from Na_(2)SeO_(3) for 21 d.The results showed that the Se concentrations in plasma,liver,kidney,pancreas,breast and thigh muscles,the activity of glutathione peroxidase(GPX)in plasma,liver and kidney,the mRNA expression levels of Gpx4,selenoprotein(Seleno)h and Selenou in liver,Selenop and Selenoh in kidney,and the protein expression levels of GPX4 in the liver and kidney of broilers were affected(P<0.05)by supplemental Se level,and increased quadratically(P<0.05)with the increase of supplemental Se level.The estimates of optimal dietary Se levels were 0.10 to 0.49 mg/kg based on the fitted broken-line or asymptotic models(P<0.0001)of the above Se concentration indices,and 0.08 to 0.37 mg/kg based on the fitted brokenline,quadratic or asymptotic models(P<0.007)of the above selenoprotein expression indices.These results indicate that the optimal dietary Se levels would be 0.49 mg/kg to support the maximum Se concentrations and 0.37 mg/kg to support the full expression of selenoproteins in plasma and various tissues of broilers fed a corn-soybean meal diet from 22 to 42 d of age.

Physiological Function of Selenium in Plants

The global understanding of selenium(Se)in plant biology mainly comes from the fields of medicine and animal science,while the research on Se in plant biology in the field of plant science lags behind.This paper summarized the physiological functions of Se in plants.These studies indicate that Se can promote plant seed development and growth and plant photosynthesis,increase plant economic yield and quality,and enhance plant antioxidant capacity and resistance to stress.However,its effects have a"dual"character,and its concentration or dosage range is very narrow.At appropriate concentrations,Se has an important impact on the physiological processes of plants and is a beneficial element for many plants to maintain health and good growth and development.

Selenium supplementation in thyroid associated ophthalmopathy: an update

·The therapeutic effect of selenium(Se)has already been proven in thyroid disease and thyroid associated ophthalmopathy(TAO).In spite of clear scientific proof of its benefits in TAO,there appears to be no clear agreement among the clinicians regarding its optimum dose,duration of the treatment,efficacy and safety to date.In this review,the author summarises the findings of 135 English language articles published on this subject over the past four decades from 1973 to 2013.The regulation and metabolism of thyroid hormones require a steady supply of Se and recent studies have revealed several possible mechanisms by which Se improves the severity of thyroid disease and TAO.These mechanisms include 1)inhibitory effect of HLA-DR molecule expression on thyrocytes;2)profound reductions of thyroid stimulating hormone(TSH)receptor antibodies(TSHR-Ab)and TPO antibodies(TPO-Ab);3)prevention of dysregulation of cell-mediated immunity and B cell function;4)neutralising reactive oxygen species(ROS)and inhibition of redox control processes required for the activation,differentiation and action of lymphocytes,macrophages,neutrophils,natural killer cells involved in both acute and chronic orbital inflammation in TAO;5)inhibition of expression of proinflammatory cytokines and 6)inhibition of prostaglandin and leukotriene synthesis.An increased oxidative stress has been observed in both acute and chronic phases of thyroid disease with raised tissue concentrations of ROS.The benefits of Se supplementation in individuals with TAO appear to be proportionate to the degree of systemic activity of the thyroid disease.The maximal benefit of Se supplementation is therefore seen in thesubjects who are hyperthyroid.Restoration of euthyroidism is one of the main goals in the management of TAO and when anti-thyroid drugs are combined with Se,the patients with Graves’disease(GD)and autoimmune thyroiditis(AIT)achieved euthyroidism faster than those treated with anti-thyroid drugs alone.Se status of normal adult humans can vary widely and Se supplementation may confer benefit only if serum Se levels are insufficient.The author recommends that serum Se levels of patients with TAO to be assessed prior to and during Se supplementation at regular intervals to avoid potential iatrogenic chronic Se overdose.

Selenium’s Utility in Mercury Toxicity: A Mini-Review

Purpose: This review of the literature intends to provide readers an understanding of the prophylactic and antidotal usefulness of selenium (Se) for mercury (Hg) toxicity. We will provide an explanation of Hg and Se interactions for potential remediation options to contaminated ecosystems. Design/methodology/approach: In this mini-review, we discuss mechanistic aspects between Hg and Se, the implication for health outcomes, and its usefulness in the ecological recovery of Hg contaminated areas. Findings: Mercury has a strong affinity for Se, resulting in Se-dependent enzymes and proteins’ deactivation with devastating consequences to the host. It is likely that Hg’s toxicity results in Se deficiency. Selenium compounds can have prophylactic or antidotal effects to prevent or reverse the adverse toxicity action of Hg exposure. Current research indicates that the chemical interactions between Hg and Se are unique. The Hg capturing capacity of Se is a million times higher than sulfur compounds and results in inactive complexes. Practical implications: Future work can target engineering methods for technologies that can reduce the toxicity of Hg in the environment. Originality/value: The unique interactions between the elements are that Hg can compromise Se dependent enzymes;however, pharmacologic doses of Se can prevent or modulate the toxic effects of Hg. Paper type: Literature review.

Study on Extraction Method of Selenium-enriched Rice

[Objectives] The aims were to optimize the extraction process of selenoproteins from selenium-enriched rice in Guangxi and provide references for the intensive processing and comprehensive utilization of selenium protein resources. [Methods]Selenium-enriched rice was used as materials to extract selenoproteins by phosphate buffer extraction method and to optimize the extraction process of selenoproteins by using the orthogonal experiment. Proteins and selenium content was measured by Coomassie Brilliant Blue G-250 reagent and AFS（ atomic fluorescence spectrometry） respectively. [Results] The most significant factor affecting extraction of rice Selenoproteins was extraction NaO H concentration,followed by the ratio of solid-liquid,temperature and then extraction time. The optimum extraction conditions of selenoproteins from rice were extraction temperature of 50 ℃,NaO H concentration of 0. 14 mol/L,extraction time of 5 h,and solid-liquid ratio of 1∶ 30. [Conclusions]The alkali extraction process optimized by orthogonal test could effectively improve the extraction rate of selenoproteins,and the optimized process parameters could be popularized and applied in practical production.

Selenoprotein W cDNAs From Five Species of Animals

The nucleotide sequences of the open reading frames of cDNAs for selenoprotein W from skeletal muscle of rat, mouse, sheep, rhesus monkey and human are reported. Theoretical translation of the coding sequences indicated highly similar proteins of 88 (mouse and rat) or 87 (human, monkey and sheep) amino acids. In 73 of 88 positions the specified amino acids are identical for all five proteins. TGA encoding selenocysteine is the 13th codon of all the cDNAs. The rnouse, rat and sheep open reading frames terminate with TGA but the human and rhesus monkey coding regions terminate with TAA. The encoded amino acid sequences are identical for the rat and mouse proteins, and for the human and monkey proteins. The similarity of the cDNAs continues in the 3' noncoding regions through the putative selenocysteine insertion sequence (SEClS) elements which are required for correct interpretation of the selenocysteine codon. The region between the SECIS elements and the polyadenylation signals showed much lower similarity. The cloned rat gene for selenoprotein W is 5000 bases long,with the 663 bases of the cDNA in six exons. The transcription start site was identified by nuclease protection assay to be 16 bases upstream of the longest cDNA clone. A canonical TATA box occurs 150 bases upstream, but the assay did not indicate the presence of longer mRNAs

Selenogenome and AMPK signal insight into the protective effect of dietary selenium on chronic heat stress-induced hepatic metabolic disorder in growing pigs

Background:Chronic heat stress(CHS)disrupts hepatic metabolic homeostasis and jeopardizes product quality of pigs.Selenium(Se)may regulate the metabolic state through affect selenoprotein.Thus,we investigate the protective effect of dietary hydroxy-4-methylselenobutanoic acid(HMSeBA)on CHS induced hepatic metabolic disorder in growing pigs,and the corresponding response of selenoprotein.Methods:Forty crossbreed growing pigs were randomly assigned to five groups:control group raised in the thermoneutral environment(22±2℃)with basal diet;four CHS groups raised in hyperthermal condition(33±2℃)with basal diet and supplied with 0.0,0.2,0.4,and 0.6 mg Se/kg HMSeBA,respectively.The trial lasted 28 d.The serum biochemical,hepatic metabolism related enzyme,protein and gene expression and 25 selenoproteins in liver tissue were determined by real-time PCR,ELISA and western blot.Results:CHS significantly increased the rectal temperature,respiration rate,serum aspartate aminotransferase(AST)and low-density lipoprotein cholesterol(LDL-C)of pigs,up-regulated hepatic heat shock protein 70(HSP70)and induced lower liver weight,glycogen content,hepatic glucokinase and glutathione peroxidase(GSH-Px).The CHSinduced liver metabolic disorder was associated with the aberrant expression of 6 metabolism-related gene and 11 selenoprotein encoding genes,and decreased the protein abundance of GCK,GPX4 and SELENOS.HMSeBA improved anti-oxidative capacity of liver.0.4 or 0.6 mg Se/kg HMSeBA supplementation recovered the liver weight,glycogen content and rescue of mRNA abundance of genes related to metabolism and protein levels of GCK.HMSeBA supplementation changed expressions of 15 selenoprotein encoding genes,and enhanced protein expression of GPX1,GPX4 and SELENOS in the liver affected by CHS.CHS alone showed no impact while HMSeBA supplementation increased protein levels of p-AMPKαin the liver.Conclusions:In summary,HMSeBA supplementation beyond nutrient requirement mitigates CHS-induced hepatic metabolic disorder,recovered the liver glycogen content and the processes that are associated with the activation of AMPK signal and regulation of selenoproteins in the liver of growing pigs.

Selenocysteine tRNAs as Central Components of Selenoprotein Biosynthesis in Eukaryotes

Selenocysteine (Sec) tRNAs serve as carrier molecules for the biosynthesis of Sec from serine and to donate Sec to protein in response to specific UGA codons. In this study, we describe the current status of Sec tRNAs in higher animals and further we exarnine: (i) the Sec tRNA population in Drosophila; (ii) transcription of the Sec tRNA in vivo (in Xenopus oocytes) and in vitro (in Xenopus oocyte extracts); (iii) the effect of selenium on the Sec tRNA population in various rat tissues following replenishment of extremely selenium deficient rats with this element; and (iv) the biosynthesis of the modified bases on Sec tRNA in Xenopus oocytes

SEPS1——新发现的炎症相关基因(英文)

Selenoprotein S1(SEPS1) ,一种新发现的对内质网的应激反应和炎症控制起作用的基因。近来的研究结果显示SEPS1与炎症细胞因子的产生存在直接的联系,可能在炎症介导的IDDM以及一些其他的免疫异常中起主要作用。

Selenium and Iodine Deficiencies and Selenoprotein Function

This paper reviews some recent findings on the interactions between selenium deficiency and iodine deficency. Both micronutrients can control the levels of selenoprotein mRNAs, particularly in the thyroid and brain. When selenium and iodine supplies are limiting the compensatory mechanisms work to minimise adverse effects on thyroid hormone metabolsm and thus neurological developtnent. The mechanisms for regulation of selenoproteins in selenium and iodine deficiency are however very tissue-specific. For example, unlike the brain and thyroid,brown adipose tissue is unable to retain selenoproteins in selenium and iodine deficiency and is therefore at greater risk from injurious effects of the deficiencies.

Biological Functions of Selenoprotein Iodothyronine Deiodinase and its Expression in Osteoarthritis

Objective Iodothyronine deiodinases(DIOs)are important selenoproteins that play a key role in the bone and joint diseases.Osteoarthritis(OA)is the most prevalent joint disease especially in elders.This bioinformatic analysis was performed to explore the role of DIOs in OA pathogenesis.Methods The biological functions of selenoprotein DIOs were analyzed by bioinformatic techniques,mcluding GenCLip 3.0,Database for Annotation,Visualization and Integrated Discovery(DAVID),STRING,Cytoscape,and Network Analyst.The expression of DIOs in the healthy individuals and OA patients was determined by mining OA-related microarray data in the gene expression omnibus(GEO)database of National Center for Biotechnology Information and performing a Meta-analysis of the data with Review Manager 5.3.Results Cluster analysis revealed that the function of the DIOs was associated with thyroid hormone receptor and iodothyronine;GO analysis showed that DIOs were mainly involved in biological processes,such as ethanol metabolism and phenol-containing compound metabolism and primarily involved in the cytochrome P450 metabolism of exogenous organisms and thyroid hormone signaling;SULT1A1 was the core node of the PPI network;miRNAs and thyroid hormones had some iterations with DIO1 and DI02;Meta-analysis showed that DIO3 expression was significantly up-regulated in OA patients(SMD=0.31,95%CI:0.03,0.59,P=0.03).Conclusions The main biological functions of DIOs were closely associated with the regulation of thyroid hormone.And the up-regulated expression of DIO3 may have crucial impact on the occurrence of OA.

RNA and Protein Requirements for Eukaryotic Selenoprotein Synthesis

Selenium has been recognized as an essential nutrient in animals since the 1950s. Demonstration of the role of dietary selenium in protection from oxidative stress foIlowed in the early 1970s, and was largely attributed to its presence as an integral part of cellular glutathione peroxidase. However, the functions of this enzyme did not explain many of the other effects of selenium deficiency. The identification of other mammalian selenoproteins during the last few years has provided new insights into the functions of this trace nutrient. The discovery that type 1 deiodinase (D1) is a selenoenzyme, in addition to unveiling an essential role for selenium in thyroid hormone action, has had more far-reaching implications. Studies of this protein opened the door for investigation of the requirements for eukaryotic selenoprotein synthesis,and the features that distinguish this pathway from the corresponding prokaryotic pathway.Selenium is present in a number of prokaryotic and eukaryotic proteins in the form of the unusual amino acid, selenocysteine. Incorporation of selenocysteine into these proteins requires a novel translation step in which UGA specifies selenocysteine insertion. Since UGA codons are typically recognized as translation stop signals, an intriguing question is raised: How does a cell recognize and distinguish a UGA selenocysteine codon from a UGA stop codon? In this review, we will focus on what is known about selenocysteine incorporation in eukaryotes, briefly summarizing initial studies and discussing a few recent advances in our understanding of this unique 'recoding' process

Structural Analysis of Predicted HIV-1 Secis Elements

Incorporation of Selenocysteine into protein requires an RNA structural motif, SECIS (Selenocysteine insertion sequence) element that, along with other factors, demarcates UGA-Sec from the UGA termination codon, for expression of Selenoproteins (in case of eukaryotes). It has been predicted that during HIV infection, several functional viral selenoproteins are expressed and synthesis of these viral selenoproteins deplete the selenium level of the host. It might be that even the viral genome has the SECIS elements in their Selenoprotein mRNA, and during infection, the host cellular machinery is transformed in such a way that the human Sec tRNA binds to the viral Selenoprotein mRNA, instead of binding to its own Selenoprotein mRNA, thus leading to expression of viral selenoproteins. This hypothesis was tested in this study by identifying the SECIS elements in the HIV-1 genome and further predicting their secondary and tertiary structures. We then tried to dock these tertiary structures with human Sec tRNA. Here we report putatively the presence of 3215 SECIS elements in the HIV-1 genome and that the human Sec tRNAsec binds to the viral SECIS elements present in the viral selenoprotein mRNA. Based on an earlier finding, it was observed that atoms of A8 and U9, which present in human Sec tRNA, are the possible key sites for binding.