Screening of Extracellular Binding Proteins of Rice Receptor-like Kinase CR4 by the Yeast Two-hybrid

[Objective] The research aimed to find the extracellular binding proteins of CR4.[Method] The extracellular domain of OsCR4 was as the bait protein,and the yeast two-hybrid was used to screen cDNA library of seedling which was cultivated 14 d.[Result] A lot of proteins which included a peroxide B（D26484）,a methionine thioredoxin reductase（ABF96078）and an unknown function protein were gained.[Conclusion] It provided the theory basis for studying the signal transduction mechanism of CR4.

GATA binding protein 2 mediated ankyrin repeat domain containing 26 high expression in myeloid-derived cell lines

BACKGROUND Thrombocytopenia 2,an autosomal dominant inherited disease characterized by moderate thrombocytopenia,predisposition to myeloid malignancies and normal platelet size and function,can be caused by 5’-untranslated region(UTR)point mutations in ankyrin repeat domain containing 26(ANKRD26).Runt related transcription factor 1(RUNX1)and friend leukemia integration 1(FLI1)have been identified as negative regulators of ANKRD26.However,the positive regulators of ANKRD26 are still unknown.AIM To prove the positive regulatory effect of GATA binding protein 2(GATA2)on ANKRD26 transcription.METHODS Human induced pluripotent stem cells derived from bone marrow(hiPSC-BM)INTRODUCTION Ankyrin repeat domain containing protein 26(ANKRD26)acts as a regulator of adipogenesis and is involved in the regulation of feeding behavior[1-3].The ANKRD26 gene is located on chromosome 10 and shares regions of homology with the primate-specific gene family POTE.According to the Human Protein Atlas database,the ANKRD26 protein is localized to the Golgi apparatus and vesicles,and its expression can be detected in nearly all human tissues[4].Moreover,UniProt annotation revealed that ANKRD26 is localized in the centrosome and contains coiled-coil domains formed by spectrin helices and ankyrin repeats[5,6].The most common disease related to ANKRD26 is thrombocytopenia 2(THC2),which is a rare autosomal dominant inherited disease characterized by lifelong mild-to-moderate thrombocytopenia and mild bleeding[7-9].Caused by the variants in the 5’-untranslated region(UTR)of ANKRD26,THC2 is defined by a decrease in the number of platelets in circulating blood and results in increased bleeding and decreased clotting ability[8,10].Due to the point mutations that occur in the 5’-UTR of ANKRD26,its negative transcription factors(TFs),Runt related transcription factor 1(RUNX1)and friend leukemia integration 1(FLI1),lose their repression effect[11].The persistent expression of ANKRD26 increases the activity of the mitogen activated protein kinase and extracellular signal regulated kinase 1/2 signaling pathways,which are potentially involved in the regulation of thrombopoietin-dependent signaling and further impair proplatelet formation by megakaryocytes(MKs)[11].However,the positive regulators of ANKRD26,which might be associated with THC2 pathology,are still unknown.

Fatty acid binding protein 5 is a novel therapeutic target for hepatocellular carcinoma

BACKGROUND Hepatocellular carcinoma(HCC)is an aggressive subtype of liver cancer and is one of the most common cancers with high mortality worldwide.Reprogrammed lipid metabolism plays crucial roles in HCC cancer cell survival,growth,and evolution.Emerging evidence suggests the importance of fatty acid binding proteins(FABPs)in contribution to cancer progression and metastasis;however,how these FABPs are dysregulated in cancer cells,especially in HCC,and the roles of FABPs in cancer progression have not been well defined.AIM To understand the genetic alterations and expression of FABPs and their associated cancer hallmarks and oncogenes in contributing to cancer malignancies.METHODS We used The Cancer Genome Atlas datasets of pan cancer and liver hepatocellular carcinoma(LIHC)as well as patient cohorts with other cancer types in this study.We investigated genetic alterations of FABPs in various cancer types.mRNA expression was used to determine if FABPs are abnormally expressed in tumor tissues compared to non-tumor controls and to investigate whether their expression correlates with patient clinical outcome,enriched cancer hallmarks and oncogenes previously reported for patients with HCC.We determined the protein levels of FABP5 and its correlated genes in two HCC cell lines and assessed the potential of FABP5 inhibition in treating HCC cells.RESULTS We discovered that a gene cluster including five FABP family members(FABP4,FABP5,FABP8,FABP9 and FABP12)is frequently co-amplified in cancer.Amplification,in fact,is the most common genetic alteration for FABPs,leading to overexpression of FABPs.FABP5 showed the greatest differential mRNA expression comparing tumor with non-tumor tissues.High FABP5 expression correlates well with worse patient outcomes(P<0.05).FABP5 expression highly correlates with enrichment of G2M checkpoint(r=0.33,P=1.1e-10),TP53 signaling pathway(r=0.22,P=1.7e-5)and many genes in the gene sets such as CDK1(r=0.56,P=0),CDK4(r=0.49,P=0),and TP53(r=0.22,P=1.6e-5).Furthermore,FABP5 also correlates well with two co-expressed oncogenes PLK1 and BIRC5 in pan cancer especially in LIHC patients(r=0.58,P=0;r=0.58,P=0;respectively).FABP5high Huh7 cells also expressed higher protein levels of p53,BIRC5,CDK1,CDK2,and CDK4 than FABP5low HepG2 cells.FABP5 inhibition more potently inhibited the tumor cell growth in Huh7 cells than in HepG2 cells.CONCLUSION We discovered that FABP5 gene is frequently amplified in cancer,especially in HCC,leading to its significant elevated expression in HCC.Its high expression correlates well with worse patient outcome,enriched cancer hallmarks and oncogenes in HCC.FABP5 inhibition impaired the cell viability of FABP5high Huh7 cells.All these support that FABP5 is a novel therapeutic target for treating FABP5high HCC.

Potential regulatory mechanism and clinical significance of synaptotagmin binding cytoplasmic RNA interacting protein in colorectal cancer

BACKGROUND Colorectal cancer(CRC)causes many deaths worldwide.Synaptotagmin binding cytoplasmic RNA interacting protein(SYNCRIP)is an RNA-binding protein that plays an important role in multiple cancers by epigenetically targeting some genes.Our study will examine the expression,potential effect,biological function and clinical value of SYNCRIP in CRC.AIM To examine the expression,potential effect,biological function and clinical value METHODS The expression of SYNCRIP was examined by immunohistochemistry arrays and high-throughput data.The effect of SYNCRIP gene in CRC cell growth was evaluated by CRISPR-Cas9 technology.The target genes of SYNCRIP were calculated using various algorithms,and the molecular mechanism of SYNCRIP in CRC was explored by mutation analysis and pathway analysis.The clinical value of SYNCRIP in prognosis and radiotherapy was revealed via evidence-based medicine methods.RESULTS The protein and mRNA levels of SYNCRIP were both highly expressed in CRC samples compared to nontumorous tissue based on 330 immunohistochemistry arrays and 3640 CRC samples.Cells grew more slowly in eleven CRC cell lines after knocking out the SYNCRIP gene.SYNCRIP could epigenetically target genes to promote the occurrence and development of CRC by boosting the cell cycle and affecting the tumor microenvironment.In addition,CRC patients with high SYNCRIP expression are more sensitive to radiotherapy.CONCLUSION SYNCRIP is upregulated in CRC,and highly expressed SYNCRIP can accelerate CRC cell division by exerting its epigenetic regulatory effects.In addition,SYNCRIP is expected to become a potential biomarker to predict the effect of radiotherapy.

Maintaining cholesterol homeostasis: Sterol regulatory element-binding proteins

The molecular mechanism of how hepatocytes maintain cholesterol homeostasis has become much more transparent with the discovery of sterol regulatory element binding proteins (SREBPs) in recent years. These membrane proteins aremembers of the basic helix-loop-helix-leucine zipper (bHLHZip) family of transcription factors. They activate the expression of at least 30 genes involved in the synthesis of cholesterol and lipids. SREBPs are synthesized as precursor proteins in the endoplasmic reticulum (ER), where they form a complex with another protein, SREBP cleavage activating protein (SCAP). The SCAP molecule contains a sterol sensory domain. In the presence of high cellular sterol concentrations SCAP confines SREBP to the ER. With low cellular concentrations, SCAP escorts SREBP to activation in the Golgi. There, SREBP undergoes two proteolytic cleavage steps to release the mature, biologically active transcription factor, nuclear SREBP (nSREBP). nSREBP translocates to the nucleus and binds to sterol response elements (SRE) in the promoter/enhancer regions of target genes. Additional transcription factors are required to activate transcription of these genes. Three different SREBPs are known, SREBPs-1a, -1c and -2. SREBP-1a and -1c are isoforms produced from a single gene by alternate splicing. SREBP-2 is encoded by a different gene and does not display any isoforms. It appears that SREBPs alone, in the sequence described above, can exert complete control over cholesterol synthesis, whereas many additional factors (hormones, cytokines, etc.) are required for complete control of lipid metabolism. Medicinal manipulation of the SREBP/SCAP system is expected to prove highly beneficial in the management of cholesterol-related disease.

Molecular Characterization, Expression Patterns and Binding Properties of Two Pheromone-Binding Proteins from the Oriental Fruit Moth, Grapholita molesta(Busck)

Insect pheromone-binding proteins （PBPs） play important roles in transporting hydrophobic pheromone components across the sensillum lymph to the surface of olfactory receptors （ORs）. However, the PBPs of the oriental fruit moth, Grapholita molesta, an important destructive pest of stone fruits worldwide, are not well characterized. In this study, two new putative PBP genes, GmolPBP2 and GmolPBP3, were identiifed from G. molesta antennae. The deduced amino-acid sequences of these two putative PBP genes are characteristic of the odorant binding protein family, containing six conserved cysteine residues. The genomic DNA sequence of each gene contained two introns. However, the lengths and positions of the introns differed. RT-PCR analyses revealed that the two GmolPBP genes are only expressed in the antennae of female and male moths. Quantitative real-time PCR indicated that the transcription levels of GmolPBP2 are far greater than those of GmolPBP3 in both female and male antennae. GmolPBP3 showed higher transcription levels in female antennae than in male antennae, while GmolPBP2 showed similar transcription levels in both female and male antennae. The transcript levels of both genes were signiifcantly different in premating and post-coitum individuals, implying that mating affects the process of sex pheromone reception. To better understand the functions, two GmolPBPs were expressed in Escherichia coli, and the ligand binding assays were conducted. Results showed that GmolPBP2 has strong binding afifnities to two sex pheromone components, E8-12：Ac and Z8-12：Ac, as well as weaker binding afifnities to Z8-12：OH and 12：OH. GmolPBP2 also bound some ordinary odor molecules. However, the afifnity of GmolPBP3 to both sex pheromones and ordinary odor molecules was very weak. These results show that GmolPBP2 plays the main role in pheromone discrimination and recognition in the oriental fruit moth.

Endonuclease-rolling circle amplification-based method for sensitive analysis of DNA-binding protein

A sensitive approach for the qualitative detection of DNA-binding protein on the microarray was developed. DNA complexes in which a partial duplex region is formed from a biotin-primer and a circle single strand DNA （ssDNA） were spotted on a microarray. The endonuclease recognition site （ERS） and the DNA-binding sites （DBS） were arranged side by side within the duplex region. The working principle of the detection system is described as follows： when the DNA-binding protein capture the DBS, the endonuclease could not attach to the ERS, and the immobilized primer in the DNA complex could be extended along the circle ssDNA by rolling circle amplification （RCA）. When no protein protects the DBS, the ERS could be attacked by the endonuclease and subsequently no rolling circle amplification occurs. Thereby we can detect the sequence specific DNA-binding activity with high-sensitivity due to the signal amplification of RCA.

Hippocampal expression of synaptic structural proteins and phosphorylated cAMP response element-binding protein in a rat model of vascular dementia induced by chronic cerebral hypoperfusion

The present study established a rat model of vascular dementia induced by chronic cerebral hypoperfusion through permanent ligation of bilateral common carotid arteries.At 60 days after modeling,escape latency and swimming path length during hidden-platform acquisition training in Morris water maze significantly increased in the model group.In addition,the number of accurate crossings over the original platform significantly decreased,hippocampal CA1 synaptophysin and growth-associated protein 43 expression significantly decreased,cAMP response element-binding protein expression remained unchanged,and phosphorylated cAMP response element-binding protein expression significantly decreased.Results suggested that abnormal expression of hippocampal synaptic structural protein and cAMP response element-binding protein phosphorylation played a role in cognitive impairment following chronic cerebral hypoperfusion.

AU-rich element-binding proteins in colorectal cancer

Trans-acting factors controlling mRNA fate are critical for the post-transcriptional regulation of inflammation-related genes, as well as for oncogene and tumor suppressor expression in human cancers. Among them, a group of RNA-binding proteins called "Adenylate-Uridylate-rich elements binding proteins"(AUBPs)control mRNA stability or translation through their binding to AU-rich elements enriched in the 3'UTRs of inflammation-and cancer-associated mRNA transcripts. AUBPs play a central role in the recruitment of target mRNAs into small cytoplasmic foci called Processing-bodies and stress granules(also known as P-body/SG). Alterations in the expression and activities of AUBPs and Pbody/SG assembly have been observed to occur with colorectal cancer(CRC)progression, indicating the significant role AUBP-dependent post-transcriptional regulation plays in controlling gene expression during CRC tumorigenesis.Accordingly, these alterations contribute to the pathological expression of many early-response genes involved in prostaglandin biosynthesis and inflammation,along with key oncogenic pathways. In this review, we summarize the current role of these proteins in CRC development. CRC remains a major cause of cancer mortality worldwide and, therefore, targeting these AUBPs to restore efficient post-transcriptional regulation of gene expression may represent an appealing therapeutic strategy.

Ligand-binding properties of three odorant-binding proteins of the diamondback moth Plutella xylostella

Strategies for insect population control are currently targeting chemical communication at the molecular level. The diamondback moth Plutella xylostella represents one of the most serious pests in agriculture, however detailed information on the proteins mediating olfaction in this species is still poor. This species is endowed with a repertoire of a large number of olfactory receptors and odorant binding proteins（OBPs）. As a contribution to map the specificities of these chemical sensors in the moth and eventually unrave l the complexity of chemodetection, we have measured the affinities of three selected OBPs to a series of potential odorants. Three proteins are highly divergent in their amino acid sequences and show markedly different expression profiles. In fact, PxylOBP3 is exclusively expressed in the antennae of both sexes, PxylOBP9 is male specific and present only in antennae and reproductive organs, while PxylOBP19, an unusual OBP with nine cysteines, is ubiquitously present in all the organs examined. Such expression pattern suggests that the last two proteins may be involved in non-chemosensory functions. Despite such differences, the three OBPs exhibit similar binding spectra, together with high selectivity. Among the 26 natural compounds tested, only two proved to be good ligands, retinol and coniferyl aldehyde. This second compound is particularly interesting being part of the chemical pathway leading to regeneration of lignin, one of the defense strategies of the plant against insect attack, and might find applications as a repellent for P. xylostella and other pests.

Characterization and Expression Analysis of Four Glycine-Rich RNA-Binding Proteins Involved in Osmotic Response in Tobacco (Nicotiana tabacum cv. Xanthi)

Plants have developed many signals and specific genes＇ regulations at both transcriptional and post-transcriptional levels in order to tolerate and adapt to various environmental stresses. RNA-binding proteins （RBPs） play crucial roles in the post- transcriptional regulation via mRNA splicing, polyadenylation, sequence editing, transport, mRNA stability, mRNA localization, and translation. In this paper, four cDNAs of glycine-rich RNA-binding proteins （GR-RBPs）, named NtRGP-la, -lb, -2, and -3, were isolated from Nicotiana tabacum by RT-PCR analysis, and special emphases were given to the sequences alignment, phylogenetic analysis and gene expression. Sequences alignment revealed minor difference of cDNA sequences, but no difference of deduced proteins between N. sylvestris and N. tabacum. Phylogenetic alignment revealed that four cDNAs in tobacco were clustered into two different groups. NtRGP-2 and -3 were evolutionarily closest to Arabidopsis GR-RBPs genes and related to animal GR-RBPs genes, while NtRGP-la and -lb were closest to Gramineae GR-RBPs genes. The expression analyses of these four NtRGPs in response to different abiotic stresses revealed the similar expression pattern. Moreover, the four NtRGPs, especially NtRGP-la and NtRGP-3, were strongly induced by stresses including water, wound, cold, and high temperature, weakly induced by PEG, drought and SA, while reduced by NaC1 and unaffected by ABA treatment. The fact that all of these abiotic stresses included in our experiments affected the water balance and resulted in osmotic stress on cellular level, suggests that NtRGPs in tobacco should be a family of crucial osmosis-related proteins, and may play a key role in signal transduction with ABA-independent pathway under abiotic stresses.

Role of oxysterol-binding protein-related proteins in malignant human tumours

The oxysterol-binding protein-related protein(ORP)family is a group of proteins that mediate oxysterol metabolism and bioactivity in cells.ORPs constitute a large family of lipid transfer proteins.Much of the current evidence indicates that certain members of the family of oxysterol-binding proteins(OSBPs)can lead to cancer.Many studies have revealed the putative roles of OSBPs in various cancer types.However,the exact effects and mechanisms of action of members of the OSBP/ORP family in cancer initiation and progression are currently unclear.This review focuses on ORP family members that can accelerate human tumour cell proliferation,migration,and invasion.The mechanisms and functions of various ORPs are introduced in detail.We also attempt to identify the roles of these proteins in malignant tumours with the ultimate aim of determining the exact role of the OSBP/ORP family in human tumour cells.

Comparison of ligand migration and binding in heme proteins of the globin family

The binding of small diatomic ligands such as carbon monoxide or dioxygen to heme proteins is among the simplest biological processes known. Still, it has taken many decades to understand the mechanistic aspects of this process in full detail. Here, we compare ligand binding in three heme proteins of the globin family, myoglobin, a dimeric hemoglobin, and neuroglobin. The combination of structural, spectroscopic, and kinetic experiments over many years by many laboratories has revealed common properties of globins and a clear mechanistic picture of ligand binding at the molecular level. In addition to the ligand binding site at the heme iron, a primary ligand docking site exists that ensures efficient ligand binding to and release from the heme iron. Additional, secondary docking sites can greatly facilitate ligand escape after its dissociation from the heme. Although there is only indirect evidence at present, a preformed histidine gate appears to exist that allows ligand entry to and exit from the active site. The importance of these features can be assessed by studies involving modified proteins（via site-directed mutagenesis） and comparison with heme proteins not belonging to the globin family.

Advances on Plant Pathogenic Mycotoxin Binding Proteins

Toxin-binding protein is one of the key subjects in plant pathogenic mycotoxin research. In this paper, new advances in toxin-binding proteins of 10 kinds of plant pathogenic mycotoxins belonging to Hel-minthosporium,Alternaria,Fusicoccum,Verticillium were reviewed, especially the techniques and methods of toxin-binding proteins of HS-toxin, HV-toxin, HMT-toxin, HC-toxin. It was proposed that the isotope-labeling technique and immunological chemistry technique should be combined together in research of toxin-binding protein, which will be significant to study the molecular recognition mechanism between host and pathogenic fungus.

Identification of AOSC-binding proteins in neurons

Acidic oligosaccharide sugar chain （AOSC）, a D-mannuronic acid oligosaccharide, derived from brownalgaepolysaccharide, has been completed Phase I clinical trial in China as an anti-Alzheimer＇s Disease （AD） drug candidate. The identification of AOSC-binding protein（s） in neurons is very important for understanding its action mechanism. To determine the binding protein（s） of AOSC in neurons mediating its anti-AD activities, confocal microscopy, affinity chromatography, and liquid chromatography-tandem mass spectrometry （LC-MS/MS） analysis were used. Confocal microscopy analysis shows that AOSC binds to SH-SY5Y cells in concentration-, time-, and temperature-dependent fashions. The AOSC binding proteins were purified by affinity chromatography and identified by LC-MS/MS analysis. The results showed that there are 349 proteins binding AOSC, including clathrin, adaptor protein-2 （AP-2） and amyloid precursor protein （APP）. These results suggest that the binding/entrance of AOSC to neurons is probably responsible for anti-AD activities.

A Structural Comparison Approach for Identifying Small Variations in Binding Sites of Homologous Proteins

A method for analyzing the protein site similarity was devised aiming at understanding selectivity of homologous proteins and guiding the design of new drugs. The method is based on calculating Cα distances between selected pocket residues and subsequent analysis by multivariate methods. Five closely related serine proteases, the coagulation factors II, VII, IX, X, and XI, were studied and their pocket similarity was illustrated by PCA clustering. OPLS-DA was then applied to identify the residues responsible for the variation. By combining these two multivariate methods, we could successfully cluster the different proteases according to class and identify the important residues responsible for the observed variation.

Cysteine Residues in Receptor Proteins： Structural Insights from Two E. coil Periplasmic Binding Proteins

Cysteine residues found in proteins have various functions such as metal binding, nitrosylation, and stabilization of structure. We have done a comparative, computational structural analysis of the cysteine residues in two proteins from bacteria to get some insight into the differences between metal binding cysteine residues and those involved in structure stabilization. The two target proteins in this study are the periplasmic mercury binding protein （MerP） and the 1-1eucine binding protein （LBP）. Both are periplasmic binding proteins from E. coli. We have shown key phenomenon that define cysteines as metal binding or structural in nature.

Novel Treatment Approach in Schizophrenia: Substitution of Glial Binding Proteins

In chronic schizophrenia, synaptic information processing is unbalanced, as shown in a model of glial-neuronal synaptic units, called tripartite synapses. The glial component of the synapse exerts a modifying function in neurotransmission since the astrocyte activated by neurotransmitters produces gliotransmitters that negatively feedback to the presynapse. It is hypothesized that in schizophrenia nonfunctional astrocytic receptors cannot be activated, thus losing their modulating function. This causes a generalization of information processing in the neuronal networks such that the brain is unable to distinguish between subjects and objects in the environment. Delusions, hallucinations and cognitive impairment occur on the behavioral level. In a model of a cholinergic tripartite synapse, it is shown that glial binding proteins modify neurotransmission by occupancy with cognate neurotransmitters temporarily turning off neurotransmission on the presynapse. Most recently, glial binding proteins have been engineered. It is proposed that the substitution of glial binding proteins may balance synaptic information processing in schizophrenia since these proteins exert a modulatory function comparable to functional astrocytic receptors. Rap- id technical developments may enable this novel treatment approach in schizophrenia.

Pathophysiological role of guanylate-binding proteins in gastrointestinal diseases

Guanylate-binding proteins(GBPs) are interferonstimulated factors involved in the defense against cellular pathogens and inflammation. These proteins, particularly GBP-1, the most prominent member of the family, have been established as reliable markers of interferon-γ-activated cells in various diseases, including colorectal carcinoma(CRC) and inflammatory bowel diseases(IBDs). In CRC, GBP-1 expression is associated with a Th1-dominated angiostatic micromilieu and is correlated with a better outcome. Inhibition of tumor growth by GBP-1 is the result of its strong antiangiogenic activity as well as its direct anti-tumorigenic effect on tumor cells. In IBD, GBP-1 mediates the anti-proliferative effects of interferon-γ on intestinal epithelial cells. In addition, it plays a protective role on the mucosa by preventing cell apoptosis, by inhibiting angiogenesis and by regulating the T-cell receptor signaling. These functions rely to a large extent on the ability of GBP-1 to interact with and remodel the actin cytoskeleton.

The expression of lacrimal androgen-binding proteins in mice Pseudomonas aeruginosa keratitis

AIM: To investigate the expression of lacrimal androgenbinding proteins(ABPs) in mice Pseudomonas aeruginosa(P. aeruginosa) keratitis.METHODS: P. aeruginosa mice model from different gender was developed by intra-stromal injection. The expression of lacrimal ABPs in lacrimal gland specimens from P. aeruginosa keratitis mice was detected by the quantitative polymerase chain reaction(q RT-PCR). Corneal virulence was evaluated based on clinical scores. To study the mechanism of lacrimal ABPs' expression, experimental subjects were pre-treated with 4 E-BP1 inhibitor, and were used to evaluate the expression levels by q RT-PCR.RESULTS: Compared with control groups, the expression of ABPα, ABPη and ABPζ in lacrimal gland from P. aeruginosa keratitis mice had no meaningful changes, while ABPε and ABPδ were significantly higher at 1 d after infection. The expression of ABPδ in lacrimal gland of male mice was higher than female mice, regardless of whether or not P. aeruginosa keratitis occurred. After 4 E-BP1 inhibitor subconjunctival injection or lacrimal injection, the expression of ABPδ and ABPε has no significant change compared with the control group.CONCLUSION: ABPδ and ABPε secreted by mice lacrimal gland may involve in the progress of alleviating the severity of corneal damage in P. aeruginosa keratitis. The expression of ABPδ and ABPε upon P. aeruginosa infection is independent of cap-dependent m RNA translation activated by 4 E-BP1.