Changes in milk fat globule membrane proteins along lactation stage of Laoshan dairy goat

The milk fat globule membrane(MFGM)is a complex structure with numerous functions,and its composition is affected by many factors.There have been few systematic investigations on goat MFGM proteome profiling during lactation.Individual milk samples from 15 healthy dairy goats were obtained at six lactation time points for investigation of the MFGM proteome using both data-independent acquisition(DIA)and data-dependent acquisition(DDA)proteomics techniques combined with multivariate statistical analysis.Using the DIA method,890 variably abundant MFGM proteins were discovered throughout the lactation cycle.From 1 to 240 d,butyrophilin subfamily 1 member A1,lipoprotein lipase,perilipin-2,and adipose triglyceride lipase were upregulated,while APOE,complement C3,clusterin,and IgG were downregulated.Furthermore,from 1 to 90 d,annexin A1,annexin A2,and antithrombin-ll were downregulated,then upregulated by d 240.Albumin had a high degree of connectedness,indicating that it was a key protein,according to protein-protein interaction research.Overall,our findings gave new insights into the biological features of MFGM protein in goat milk throughout lactation,which may aid in the creation of specialized MFGM products and infant formula.

Interactions between mycoplasma lipid-associated membrane proteins and the host cells

Mycoplamas are a group of wall-less prokaryotes widely distributed in nature, some of which are pathogenic for humans and animals. There are many lipoproteins anchored on the outer face of the plasma membrane, called lipid-associated membrane proteins (LAMPs). LAMPs are highly antigenic and could undergo phase and size variation, and are recognized by the innate immune system through Toll-like receptors (TLR) 2 and 6. LAMPs can modulate the immune system, and could induce immune cells apoptosis or death. In addition, they may associate with malignant transformation of host cells and are also con-sidered to be cofactors in the progression of AIDS.

Immunoproteomics of membrane proteins of Shigella flexneri 2a 2457T

AIM： To screen the immunogenic membrane proteins of Shigella Aexneri 2a 2457T. METHODS： The routine two-dimensional polyacrylamide gel electrophoresis （2-DE） and Western blotting were combined to screen immunogenic proteins of S. Aexneri 2a 2457T. Serum was gained from rabbits immunized with the same bacteria. Immunogenic spots were cut out from the polyacrylamide gel and digested by trypsin in-gel. Matrix-assisted laser desorption/ionization time of flight-mass spectrometry （MALDI-TOF-MS） was performed to determine the molecular weight of peptides. Electrospray ionization （ESI-MS/MS） was performed to determine the sequences of the interesting peptides. RESULTS： A total of 20 spots were successfully identified from Coomassie brilliant blue stained gels representing 13 protein entries, 5 known antigens and 8 novel antigens. A hypothetical protein （YaeT） was detected, which might be a candidate target of vaccine. CONCLUSION： Membrane proteins of S. flexneri 2a 2457T were successfully observed by 2-DE. Several known and novel antigens were identified by mass spectrum.

Antimicrobial Susceptibility and Characterization of Outer Membrane Proteins of Aeromonas hydrophila Isolated in China

Aeromonas hydrophila isolates from clinical cases （n=43） were tested against 8 antimicrobial agents and typed by outer membrane protein （OMP） pattern by using sodium dodecyl sulfate gel electrophoresis. All isolates were resistant to ampicillin （MICs, ≥16 μg mL-1） and sulfamonomethoxine （MICs≥64 μg mLl）, but susceptible to norfloxacin （MICs,≤0.5 μg mL-1）. There was a high incidence of resistance to erythromycin （90.70%） and tylosin （93.02%）, while a low incidences of resistance to ciprofloxacin （2.33%）, enrofloxacin （2.33%） and florfenicol （4.65%）. Six different outer membrane protein patterns were found among 34 isolates by analyzing proteins in the range of 22 to 50 kDa, other than 9 isolates with their respective profiles. The strains with the similar OMP profiles had similar resistances. Compared with the other strains from the same OMP patterns, NB-1, A.Pun and MR-1 had lacked the proteins in the range of 30 to 45 kDa and their resistance to florfenicol substantially increased. It is speculated that the outer membrane protein changes might correlate with decreased susceptibility to florfenicol in the three strains. Some strains which showed completely identical OMP types had a little difference in their resistance to fluoroquinolones, indicating that there might be other factors that were involved in the antimicrobial resistance of A. hydrophila.

Fluorescence Study on The Interaction Between Cisplatinand Erythrocyte Membrane Proteins

The interaction between cisplatin and erythrocyte membrane proteins was studied based on the quenching effect of cisplatin on the intrinsic fluorescence of proteins.A concentration-dependent quenching effect was observed.The presence of chloride and sulphate weakens the effect significantly.A pH-dependence was also noted with a stronger effect in acidic solution. The nature of the interaction is considered to be platinum-thiol group binding according to the effect of cisplatin on the fluorescence of FMA labeled membrane. The mechanism of the cisplatin-protein interactions was discussed based on the effect of coexisting anion

Lipid-associated membrane proteins of Mycoplasma penetrans induce production of proinflammatory cytokines in human monocytic cells

The aim of this study is to explore potential pathogenicity of Mycoplasma penetrans, and to investigate whether M. penetrans lipid-associated membrane proteins （LAMPs） could induce human monocytic cell line （THP- 1 ） to produce some proinflammatory cytokines in vitro, including interleukin- 1β （ IL- 1β）, tumor necrosis factor alpha （TNF-α）, and IL-8. THP-1 was stimulated with different concentrations of M.penetrans LAMPs and at different time to analyze the production of human IL-1β, TNF-α and IL-8. The protein levels of human IL-1β, TNF-α and IL-8 were measured by enzyme-linked immunoadsorbent assay （ELISA） and the mRNA levels of these proinflammatory cytokines were detected by reverse transcriptase-PCR （RT-PCR）. It was demonstrated in the present study that the production of IL-1β, TNF-α and IL-8 increased in dose- and time-dependent manner after stimulation with M. penetrans LAMPs in THP-1 cells. M. penetrans LAMPs also induced the expression of IL-1β, TNF-α and IL-8 mRNA. The production of IL-1β, TNF-α and IL-8 and the expression of mRNA were down-regulated by pyrrolidine dithiocarbamate （PDTC）. This study demonstrated that M. penetrans LAMPs can induce the production of proinflammatory cytokines in human monocytic cells in vitro, thus suggesting that it may be an important etiological factor.

Immunoproteomic Analysis of Bordetella bronchiseptica Outer Membrane Proteins and Identification of New Immunogenic Proteins

Bordetella bronchiseptica is a Gram-negative pathogen that causes acute and chronic respiratory infection in a variety of animals. To identify useful antigen candidates for diagnosis and subunit vaccine of B. bronchiseptica, immunoproteomic analysis was adopted to analyse outer membrane proteins of it. The outer membrane proteins extracted from B. bronchiseptica were separated by two-dimensional gel electrophoresis and analyzed by Western blotting for their reactivity with the convalescent serum against two strains. Immunogenic proteins were identified by matrix-assisted laser desorption/ionization time of flight-mass spectrometry（MALDI-TOF-MS）, a total of 14 proteins are common immunoreactive proteins, of which 1 was known antigen and 13 were novel immunogenic proteins for B. bronchiseptica. Putative lipoprotein gene was cloned and recombinantly expressed. The recombinant protein induced high titer antibody, but showed low protective indices against challenges with HB（B. bronchiseptica strain isolated from a infected rabbit）. The mortality of mice was 80% compared to 100% of positive controls. The identification of these novel antigenic proteins is an important resource for further development of a new diagnostic test and vaccine for B. bronchiseptica.

Expression of inducible nitric oxide synthase induced by lipid-associated membrane proteins of Ureaplasma urealyticum is regulated by nuclear factor κB-mediated mechanism in murine macrophages

The aim was to investigate the molecular mechanisms responsible for the inducible nitric oxide synthase （iNOS） gene expression stimulated by lipid associated membrane proteins （LAMPs） of Ureaplasma urealytictan （ U. urealyticum ）. Detection of NO, the expression of iNOS and the activation of nuclear factor κB （NF-κB） in direct response to U. urealyticum LAMPs in a murine macrophages, the effects of pyrrolidine dithiocarbamate （PDTC）, an inhibitor of NF-κB and of cycloheximide （CHX）, a protein synthase inhibitor were available. The results indicated that U. urealyticum LAMPs stimulated mouse macrophages to express iNOS and thus produce NO in dose- and time-dependent manner by activating NF-κB. The expression of iNOS, NO production and the activation of NF-κB were inhibited by U. urealyticum LAMPs combination with PDTC or CHX. In conclusion, our findings suggest that U. urealyticum may be an etiological factor to certain diseases due to its ability to stimulate the expression of iNOS, which is probably mediated through the activation of NF-κB.

Determination of the genus-specific antigens in outer membrane proteins from the strains of Leptospira interrogans and Leptospira biflexa with different virulence

Objective:To determine the existence of genus-specific antigens in outer membrane proteins (OMPs) of leptospira with different virulence. Methods: Microscope agglutination test (MAT) was applied to detect the agglutination between commercial rabbit antiserum against leptospiral genus-specific TR/Patoc I antigen and 17 strains of Leptospira interrongans belonging to 15 serogroups and 2 strains of Leptospira biflexa belonging to 2 serogroups.The outer envelopes (OEs) of L.interrogans serogroup Icterohaemorrhagiae serovar lai strain lai (56601) with strong virulence and serogroup Pomona serovar pomona strain Luo (56608) with low virulence,and L.biflexa serogroup Semaranga serovar patoc strain Patoc I without virulence were prepared by using the method reported in Auran et al.(1972).OMPs in the OEs were obtained by treatment with sodium deoxycholate. SDS-PAGE and western blot were used for analyzing the features of the OMPs on electrophoretic pattern and the immunoreactivity to the antiserum against TR/Patoc I antigen, respectively. Results:All the tested strains belonging to different leptospiral serogroups agglutinated to the antiserum against leptospiral genus-specific TR/Patoc I antigen with agglutination titers ranging from 1:256-1:512. A similar SDS-PAGE pattern of the OMPs from the three strains of leptospira with different virulence was shown and the molecular weight of a major protein fragment in the OMPs was found to be approximately 60 KDa.A positive protein fragment with approximately 32 KDa confirmed by Western blot,was able to react with the antiserum against leptospiral genus-specific TR/Patoc I antigen, and was found in each the OMPs of the three stains of leptospira.Conclusion: There are genus-specific antigens on the surface of L.interrogans and L.biflexa. The OMP with molecular weight of 32 KDa may be one of the genus-specific protein antigens of leptospira.

Antibody Therapies Targeting Complex Membrane Proteins

In analyses of protein families that may serve as drug targets,membrane-associated G-protein-coupled receptors(GPCRs)dominate,followed by ion channels,transporters,and—to a lesser extent—membrane-bound enzymes.However,various challenges put such membrane proteins among key groups of underutilized opportunities for the application of therapeutic antibodies.Antibodies hold the promise of exquisite specificity,as they are able to target even specific conformations of a particular membrane protein,as well as adaptability through engineering into various antibody formats.However,the ease of raising and isolating specific,effective antibodies targeting membrane proteins depends on many factors.In particular,the generation of specific antibodies is easier when targeting larger,simpler,extracellular domains with greater uniqueness of amino acid sequence.The rareness of such ideal conditions is illustrated by the limited number of approved biologics for targeting GPCRs and other complex membrane proteins.Challenges in developing antibodies to complex membrane proteins such as GPCRs,ion channels,transporters,and membrane-bound enzymes can be addressed by the design of the antigen,antibody-generation strategies,lead optimization technologies,and antibody modalities.A better understanding of the membrane proteins being targeted would facilitate mechanism-based drug discovery.This review describes the advantages and challenges of targeting complex membrane proteins with antibodies and discusses the preparation of membrane protein antigens and antibody generation,illustrated by select examples of success.

Generation and Identification of Monoclonal Antibody Against Porcine Adipocyte Plasma Membrane Proteins

Production of monoclonal antibody against porcine adipocyte plasma membrane proteins to explore a new way of controlling body fat deposition and improving carcass quality is discussed in this article. Membrane proteins of pig adipocyte plasma membrane proteins were extracted with the help of sucrose density gradient centrifugation, and two kinds of proteins were obtained. The monoclonal antibody （designated 3B2 and 3F3） of IgG1 and IgG2b subclass against adipocyte membrane proteins were produced by immunization, with adipocyte membrane proteins as an antigen, and its titer was 1：105 detected by enzyme-linked immunoadsorbent assay （ELISA）. The cell strains were identified by analyzing the number of chromosomes, the heat stability, the acid and alkali, the types and subtypes of immnoglobulin, and its peculiarities and affinities. Through identification, the chromosome number of hybridoma cell strains was from 80 to 100 and the strains formed good hybridomas colonies. The strains＇ affinity constants were 4.63 × 10^9 and 3.75 × 10^9 （mol L^-1）-1, respectively. At the same time, the McAb secreted was stable to environmental factors, such as, temperature, acid, alkali and so on. The monoclonal antibodies had been obtained and their specificity to porcine adipocyte plasma membrane proteins had been identified.

Immunogenicity and protective role of antigenic regions from five outer membrane proteins of Flavobacterium columnare in grass carp Ctenopharyngodon idella

Flavobacterium columnare causes columnaris disease in freshwater fi sh. In the present study, the antigenic regions of fi ve outer membrane proteins(OMPs), including zinc metalloprotease, prolyl oligopeptidase, thermolysin, collagenase and chondroitin AC lyase, were bioinformatically analyzed, fused together, and then expressed as a recombinant fusion protein in Escherichia coli. The expressed protein of 95.6 k Da, as estimated by 10% sodium dodecyl sulfate-polyacrylamide gel electrophoresis, was consistent with the molecular weight deduced from the amino acid sequence. The purifi ed recombinant protein was used to vaccinate the grass carp, C tenopharyngodon idella. Following vaccination of the fi sh their Ig M antibody levels were examined, as was the expression of I g M, Ig D and Ig Z immunoglobulin genes and other genes such as MHC Iα and MHC I I β, which are also involved in adaptive immunity. Interleukin genes( IL), including I L- 1β, IL- 8 and I L- 10, and type I and type II interferon(I FN) genes were also examined. At 3 and 4 weeks post-vaccination(wpv), signifi cant increases in Ig M antibody levels were observed in the fi sh vaccinated with the recombinant fusion protein, and an increase in the expression levels of I g M, Ig D and Ig Z genes was also detected following the vaccinations, thus indicating that an adaptive immune response was induced by the vaccinations. Early increases in the expression levels of IL and IFN genes were also observed in the vaccinated fi sh. At four wpv, the fi sh were challenged with F. column a re, and the vaccinated fi sh showed a good level of protection against this pathogen, with 39% relative percent survival(RPS) compared with the control group. It can be concluded, therefore, that the fi ve OMPs, in the form of a recombinant fusion protein vaccine, induced an immune response in fi sh and protection against F. columnare.

Extraction and identification of membrane proteins from black widow spider eggs

The eggs of oviparous animals are storehouses of maternal proteins required for embryonic development. Identification and molecular characterization of such proteins will provide much insight into the regulation of embryonic development. We previously analyzed soluble proteins in the eggs of the black widow spider （Latrodectus tredecimguttatus）, and report here on the extraction and mass spectrometric identification of the egg membrane proteins. Comparison of different lysis solutions indicated that the highest extraction of the membrane proteins was achieved with 3%-4% sodium laurate in 40 mmol/L Tris-HCI buffer containing 4% CHAPS and 2% DTT （pH 7.4）. SDS-PAGE combined with nLC- MS/MS identified 39 proteins with membranelocalization annotation, including those with structural, catalytic, and regulatory activities. Nearly half of the identified membrane proteins were metabolic enzymes involved in various cellular processes, particularly energy metabolism and biosynthesis, suggesting that relevant metabolic processes were active during the embryonic development of the eggs. Several identified cell membrane proteins were involved in the special structure formation and function of the egg cell membranes. The present proteomic analysis of the egg membrane proteins provides new insight into the molecular mechanisms of spider embryonic development.

30 and 32 kDa outer membrane proteins of Bordetella pertussis as a modulator on promoting degranulation of mast cells

The correlation between the activities of the outer menbrane proteins （OMPs） of Bordetella pertussis and the lgE-mediated asthma was investigated in the present study, in which the OMPs of B. pertussis and their components were prepared by detergent treatment and chromatography, and the molecular weights of the OMPs components were determined by SDS-PAGE. The amounts of total as well as the ovalbumin （OVA）-specific IgE induced by dead B. pertussis whole bacterial vaccine on guinea pigs were detected by ELISA. Meanwhile, the effect of the OMPs and their components to promote the degranulation of guinea pig mast cells was observed by using the mast cell degranulation test, and ELISA assay was used to measure the histatmine levels in the supematants from the mast cell cultures. Histamine sensitive test was used to demonstrate the effects of the OMPs and their components to increase the histamine lethal sensitivity in mice. It was found that four components with molecular weights of 30, 32, 38 and 69 kDa could be obtained from the OMPs of B. pertussts, and the dead whole bacteria vaccine of B. pertussis had the ability to increase the levels of the total as well as the OVA-specific IgE in sera of guinea pigs. The OMPs and their 30 and 32 kDa components demonstrated significantly enhancing effect on the degranulation of guinea pig mast cells, and the histamine levels in the supematants from the mast cell culture treated with OMPs and their 30 and 32 kDa components were also significantly increased. It is evident that the strong adjuvant activity and the enhancing effect to degranulation of mast cells and the release of histamine of certain outer membrane components of B. pertussis could be demonstrated as revealed by the results of the present study, suggesting the possibility of a close relationship between the infection of vaccination with B. pertussis and the IgE-mediated asthma.

Artificial Nucleic Acid Tractor-Directed Simultaneous Depletion of Oncogenic Membrane Proteins Without Hijacking Proteolysis-Specific Actuator

Targeted protein degradation(TPD)is an emerging tool for degrading proteins of interest,which affords an attractive modality for cancer therapy.However,the present TPD technologies must engage a proteolysis-specific actuator to initiate degradation of targeted proteins in the proteasome or lysosome.Herein,we report an artificial tractor that can induce endocytosis-mediated protein depletion without hijacking a proteolysis-specific actuator.In this design,bispecific aptamer chimeras(BSACs)are established,which can bridge human epidermal growth factor receptor 2(ErbB-2),an important biomarker in a common important biomarker in cancer,with membrane proteins of interest.Taking advantage of the property of aptamer-induced endocytosis and digestion of ErbB-2,another membrane protein is translocated into the lysosome in a hitchhike-like manner,resulting in lysosomal proteolysis along with ErbB-2.This strategy frees the TPD from the fundamental limitation of proteolysis-specific actuator and allows simultaneous regulation of the quantity and function of two oncogenic receptors in a cell-type-specific manner,expanding the application scope of TPD-based therapeutics.

Functional characterization of sensory neuron membrane protein 1a involved in sex pheromone detection of Apolygus lucorum(Hemiptera:Miridae)

The mirid bug Apolygus lucorum(Hemiptera:Miridae)is a polyphagous pest that affects a wide range of host plants.Its control remains challenging mainly due to its rapid reproduction,necessitating an understanding of sex pheromone communication.The recognition of sex pheromones is vital for courtship and mating behaviors,and is mediated by various chemosensory-associated proteins.Among these,sensory neuron membrane protein(SNMP),a CD36-related protein,is suggested to play crucial roles in detecting sex pheromones.In this study,we employed transcriptomic and genomic data from A.lucorum and phylogenetic approaches,and identified four putative SNMP genes(AlucSNMP1a,AlucSNMP1b,AlucSNMP2a,and AlucSNMP2b)with full open reading frames.Expression analysis revealed the ubiquitous presence of AlucSNMP transcripts in multiple tissues,with only AlucSNMP1a exhibiting male-biased expression in the antennae,suggesting its potential role in male chemosensation.Functional analysis using the Xenopus oocyte expression system,coupled with two-electrode voltage clamp recording,demonstrated that the co-expression of AlucSNMP1a with specific pheromone receptors(PRs)and the Odorant receptor co-receptor(Orco)significantly enhanced electrophysiological responses to sex pheromones compared to the co-expression of PRs and Orco alone.Moreover,the results indicated that the presence of AlucSNMP1a not only affected the responsiveness to sex pheromones but also influenced the kinetics(activation and inactivation)of the induced signals.In contrast,the co-expression of AlucSNMP1b with AlucPR/Orco complexes had no impact on the inward currents induced by two pheromone compounds.An examination of the selective pressures on SNMP1 genes across 20 species indicated strong purifying selection,implying potential functional conservation in various insects.These findings highlight the crucial role of AlucSNMP1a in the response to sex pheromones.

The recombinant expression systems for structure determination of eukaryotic membrane proteins

Eukaryotic membrane proteins, many of which are key players in various biological processes, constitute more than half of the drug targets and represent important candidates for structural studies. In contrast to their physiological significance, only very limited number of eukaryoUc membrane protein structures have been obtained due to the technical challenges in the genera- tion of recombinant proteins. In this review, we examine the major recombinant expression systems for eukaryotic membrane proteins and compare their relative advantages and disadvantages. We also attempted to summarize the recent technical strategies in the advancement of eukaryotic membrane protein purification and crystallization.

Activation of nuclear factor κB and induction of inducible nitric oxide synthase by lipid-associated membrane proteins isolated from Mycoplasma penetrans

Background This study was designed to investigate the potential pathogenicity of Mycoplasma penetrans (M. penetrans) and its molecular mechanisms responsible for the induction of iNOS gene expression in mouse macrophages stimulated by lipid-associated membrane proteins (LAMPs) prepared from M. penetrans.Methods Mouse macrophages were stimulated with M. penetrans LAMPs to assay the production of nitric oxide (NO). The expression of inducible nitric oxide synthase (iNOS) was detected by RT-PCR and Western blotting. The activity of nuclear factor κB (NF-κB) and the effects of pyrrolidine dithiocarbamate (PDTC), an inhibitor of NF-κB, on the production of nitric oxide and the expression of iNOS were also assessed in mouse macrophages treated with M. penetrans LAMPs by indirect immunofluorescence and Western blotting.Results M. penetrans LAMPs stimulated mouse macrophages to produce nitric oxide in a dose- and time-dependent manner. The mRNA and protein levels of iNOS were also upregulated in response to LAMP stimulation and inhibited by PDTC treatment. M. penetrans LAMPs were found to trigger NF-κB activation, a possible mechanism for the induction of iNOS expression.Conclusion This study demonstrated that M. penetrans may be an important etiological factor of certain diseases due to the ability of M. penetrans LAMPs to stimulate the expression of iNOS, which is probably mediated through the activation of NF-κB.

Molecular characterization and expression of sensory neuron membrane proteins in the parasitoid Microplitis mediator (Hymenoptera: Braconidae)

Sensory neuron membrane proteins(SNMPs),homologs of the human fatty acid transport protein CD36 family,are observed to play a significant role in chemoreception,especially in detecting sex pheromone in Drosophila and some lepidopteran species.In the current study,two full‐length SNMP transcripts,MmedSNMP1 and MmedSNMP2,were identified in the parasitoid Microplitis mediator(Hymenoptera:Braconidae).Quantitative real‐time polymerase chain reaction analysis showed that the expression of MmedSNMP1 was significantly higher in antennae than in other tissues of both sexes.In addition,the MmedSNMP1 transcript was increased dramatically in newly emerged adults and there were no significant differences between adults with or without mating and parasitic experiences.However,compared with MmedSNMP1,the expression of MmedSNMP2 was widely found in various tissues,significantly increased at half‐pigmented pupae stage and remained at a relatively constant level during the following developmental stages.It was found that MmedSNMP1 contained eight exons and seven introns,which was highly conserved compared with other insect species.In situ hybridization assay demonstrated that MmedSNMP1 transcript was distributed widely in antennal flagella.Among selected chemosensory genes(odorant binding protein,odorant receptor,and ionotropic receptor genes),MmedSNMP1 only partially overlapped with MmedORco in olfactory sensory neurons of antennae.Subsequent immunolocalization results further indicated that MmedSNMP1 was mainly expressed in sensilla placodea of antennae and possibly involved in perceiving plant volatiles and sex pheromones.These findings lay a foundation for further investigating the roles of SNMPs in the chemosensation of parasitoids.

Identification and localization of two sensory neuron membrane proteins from Spodoptera fitura （Lepidoptera： Noctuidae）

Sensory neuron membrane proteins （SNMPs）, which are located on the dendritic membrane of olfactory sensory neurons （OSNs）, are proposed to be associated with odor reception in insects. Recent studies have demonstrated that SNMP1 is essential for electrophysiological responses of OSNs to the sex pheromone, cis-vaccenyl acetate （cVA） in Drosophila melanogaster. To investigate the function ofLepidoptera SNMPs, we cloned two SNMP genes, SlituSNMP1 and SltiuSNMP2, from Spodoptera litura （Lepidoptera： Noctuidae）. Sequence alignment and phylogenetic analysis showed that both genes bear the general characteristics of SNMPs, including six conserved cysteine residues and two transmembrane domains. Further expression profile experiments showed that SIituSNMP1 is mainly expressed in the antenna, while SlituSNMP2 is broadly expressed in various tissues. By in situ hybridization experiments, it was found that SlituSNMP1 expressing cells are surrounded by the SlituSNMP2 expressing cells in the pheromone sensitive sensilla, suggesting different fimctions ＆the two SNMPs in insect olfaction.