Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “CD36”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 307 records · Page 17Linked to original sources

Cd36 and molecular mechanisms of insulin resistance in the stroke-prone spontaneously hypertensive rat.

Insulin resistance is of pathogenic importance in several common human disorders including type 2 diabetes, hypertension, obesity and hyperlipidemia, but the underlying mechanisms are unknown. The spontaneously hypertensive rat (SHR) is a model of these human insulin resistance syndromes. Quantitative trait loci (QTLs) for SHR defects in glucose and fatty acid metabolism, hypertriglyceridemia, and hypertension map to a single region on rat chromosome 4. Genetic analysis of an SHR derived from a National Institutes of Health colony led to the identification of a causative mutation in the SHR Cd36. We have investigated glucose and fatty acid metabolism in the stroke-prone SHR (SHRSP). We demonstrate defects in insulin action on 2-deoxy-D-glucose transport (SHRSP 3.3 +/- 1.5 vs. 21.0 +/- 7.4 pmol x min(-1) x [20 microl packed cells](-1), SHRSP vs. WKY, respectively, P = 0.01) and inhibition of catecholamine-stimulated lipolysis (P < 0.05 at all concentrations of insulin) in adipocytes isolated from SHRSP. In contrast, basal levels of catecholamine-stimulated nonesterified free fatty acid (NEFA) release and plasma levels of NEFA are similar in SHRSP and WKY. These results are in agreement with the data on the SHR.4 congenic strain, which suggested that the QTL containing Cd36 mutations accounted for the entire defect in basal catecholamine action but only for approximately 40% of the SHR defect in insulin action. In the SHR, both abnormalities appear consequent of defective Cd36 expression. Because Cd36 sequence and expression are apparently normal in SHRSP, it is likely that the molecular mechanism for defective insulin action in this strain is caused by a gene(s) different than Cd36.

Adipocytes↗

CD36: a critical anti-angiogenic receptor.

Thrombospondin-1 (TSP-1) is a potent inhibitor of angiogenesis in vivo and of microvascular endothelial cell responses to angiogenic factors in vitro. CD36 is the cellular receptor for TSP-1 on microvascular endothelium and is necessary for its anti-angiogenic activity. The anti-angiogenic activity of TSP-1 is contained in a structural domain known as the TSP type I repeat (TSR-1). TSR-1 domains occur in many other proteins, some of which have also been shown to have anti-angiogenic activity. Structure-function analyses have determined that binding of TSP-1 to CD36 is mediated by interaction of the TSR-1 domain of TSP with a conserved domain called CLESH-1 in CD36. Histidine rich glycoprotein, a plasma and cellular protein that blocks the binding of thrombospndin-1 to CD36, inhibits the antiangiogenic response to thrombospondin and may serve to modulate the thrombospondin/CD36 anti-angiogenic pathway. Several in vivo models support the role of the TSP/CD36 system in angiogenesis and tumor growth and provide evidence that the CD36 antiangiogenic pathway offers attractive therapeutic targets.

Angiogenesis Inhibitors↗

CD36 is differentially expressed by CD8+ splenic dendritic cells but is not required for cross-presentation in vivo.

Cross-presentation allows the processing of Ags from donor cells into the MHC class I presentation pathway of dendritic cells (DCs). This is important for the generation of cytotoxic T cell immunity and for induction of self tolerance. Apoptotic cells are reported to be efficient targets for cross-presentation, and in vitro studies using human DCs have implicated CD36 in their capture. In support of a role for CD36 in cross-presentation, we show that this molecule is differentially expressed by CD8(+) splenic DCs, which previously have been identified as responsible for cross-presentation in the mouse. Three different cross-presentation models were examined for their dependence on CD36. These included cross-priming to OVA-coated spleen cells and cross-tolerance to OVA transgenically expressed in the pancreatic islet beta cells under constitutive conditions or during beta cell destruction. In these models, CD36 knockout DCs were equivalent to wild-type DCs in their capacity to cross-present either foreign or self Ags, indicating that CD36 is not essential for cross-presentation of cellular Ags in vivo.

Animals↗

Synergically increased expression of CD36, CLA-1 and CD68, but not of SR-A and LOX-1, with the progression to foam cells from macrophages.

Several species of scavenger receptors have so far been identified. However, it remains unclear which receptors are more crucial for the foam cell formation and progression. In the present study, we compared five major scavenger receptors (SR-A, CD36, CLA-1, CD68, and LOX-1) in their levels of expression at the different stages of foam cells derived from THP-1 cells. The expression of all scavenger receptors examined was up-regulated by the stimulation with TPA for 48 hours, despite the expressions of SR-A, CD36 and LOX-1 being very low before the treatment with TPA. Four to 7 days after the removal of TPA, the levels of CD36, CLA-1 and CD68 were increased significantly. In contrast, the expression of SR-A was suppressed significantly, and no change was observed in that of LOX-1. Furthermore, when the transformed macrophages were incubated with oxidized LDL, in which the uptake of [3H] cholesteryl oleoyl ether-labeled OxLDL was linear up to 7 days after the addition of OxLDL, the expression of CD36, CLA-1 and CD68 were greatly enhanced. This enhancement was more prominent than that without oxidized LDL, and the enhancement was sustained throughout the experimental period. On the other hand, SR-A was not up-regulated, and LOX-1 was down-regulated. We thus propose that CD36, CLA-1 and CD68, but not SR-A and LOX-1, may play crucial roles in the progression of macrophages to foam cells, which is a key step for the initiation of atherosclerosis.

Antigens, CD↗

Does Cd36 gene play a key role in disturbed glucose and fatty acid metabolism in Prague hypertensive hypertriglyceridemic rats?

Close links between hypertension, hypertriglyceridemia, insulin resistance and other symptoms of metabolic syndrome was demonstrated in humans and experimental animals. Quantitative trait loci for defects in glucose and fatty acid metabolism, hypertriglyceridemia and hypertension were mapped in spontaneously hypertensive rats (SHR) on chromosome 4 and defective Cd36 gene was identified in this region. Here we investigated the polymorphism of Cd36 gene in Prague hereditary hypertriglyceridemic (HTG) rats, which represent another model of genetic hypertension and metabolic syndrome. These animals were compared with NIH-derived SHR and two different normotensive control strains (WKY, LEW). In spite of the fact that HTG and SHR rats had similar metabolic disturbances, genotype analysis of PCR products has shown that Cd36 mutation was not present in HTG rats. In conclusion, we have revealed that defective Cd36 is probably a candidate gene for disorded fatty-acid metabolism, glucose intolerance and insulin resistance in NIH-derived SHR, but other genes might play a role in pathogenesis of metabolic syndrome in Prague hereditary hypertriglyceridemic rats. This is in accordance with the absence of defective Cd36 gene in original SHR from Japan.

Animals↗

Expression of CD29 on lymphoma cells and/or CD36 on microvascular endothels correlates with high serum LDH level in diffuse large B-cell lymphomas (DLBCLs) and is frequent in de novo CD5-positive DLBCLs.

Our previous study demonstrated that CD29 and CD36 mRNAs were overexpressed in de novo CD5-positive diffuse large B-cell lymphomas (CD5+ DLBCLs) compared with CD5-negative (CD5-) DLBCLs. CD29 was expressed on lymphoma cells, and CD36 on microvascular endothels. In the present study, we analyzed the clinicopathological significance of CD29 and microvascular CD36 (mvCD36) expression in many cases of DLBCLs. CD29 and CD36 expression was examined by immunohistochemistry on frozen sections of 159 specimens, consisting of 120 cases of CD5-DLBCL, 14 cases of de novo CD5+ DLBCL, 11 cases of follicular lymphoma, 8 cases of mantle cell lymphoma, and 6 cases of reactive lymphoid hyperplasia. Three cases of CD5- intravascular large B-cell lymphomas (IVLs) with hepatic intrasinusoidal infiltration were also examined. CD29+ and/or mvCD36+ DLBCL cases had significantly higher serum LDH levels compared with CD29- mvCD36- DLBCL cases. The number of CD29+ and mvCD36+ cases, and the number of CD29+ or mvCD36+ cases, were significantly higher in de novo CD5+ DLBCLs than in CD5- DLBCLs. The frequencies of CD29 and mvCD36 expression were low in follicular lymphomas, and mvCD36 was negative in reactive lymphoid hyperplasias. Liver biopsies of three IVL cases showed that CD29 was positive on lymphoma cells, and, that CD36 was expressed on hepatic sinusoids. The present study supports the notion that CD29 and/or mvCD36 expression manifests the aggressive feature of a subset of DLBCLs because of its correlation with high serum LDH levels. Furthermore, CD29 and mvCD36 expression should be evaluated in relation to the intravascular growth pattern of lymphoma cells.

Biomarkers, Tumor↗

Different expression of CD36 antigen molecule on the surface of megakaryocyte lineage leukemias and megakaryocyte leukemia cell lines MEG-01 and HEL.

Peripheral blood leukemic cells from four patients with peroxidase negative acute leukemia, which expressed neither myeloid nor lymphoid cell surface antigens, were analyzed by using monoclonal antibodies (MoAb) capable of recognizing megakaryocyte-platelet-related antigens. Leukemic cells from one case reacted with 5F1 MoAb, whereas cells from all the tested cases reacted with OKM5 MoAb, which belongs to the same CD group as 5F1 (CD36). Also, culture cells from megakaryoblastic leukemia cell line, MEG-01, and human erythroleukemia cell line, HEL, showed a different pattern of expression for the CD36 antigen molecule detected by 5F1 and OKM5 MoAb, individually. Furthermore, we have demonstrated that the epitopes recognized by 5F1 and OKM5 MoAb appear on the same CD36 molecule on the surface of HEL cells by means of the two-color analysis using FACS-IV. On the basis of our experiments, we conclude that, CD36 molecule, a receptor for TSP, is synthesized and expressed in at least two ways, inside the cells and on the surface of megakaryocyte lineage leukemias and megakaryocytic leukemia cell lines MEG-01 and HEL. This is strongly suggestive that thrombospondin (TSP)-mediated adhesion represents an alternative pathway for cytoadherence, and that CD36 expression on various kinds of cells may lack some essential modifications or components necessary for the TSP receptor activity.

Antibodies, Monoclonal↗

Mast cell growth factor modulates CD36 antigen expression on erythroid progenitors from human bone marrow and peripheral blood associated with ongoing differentiation.

To study the differentiation process of erythroid progenitors from normal human bone marrow and peripheral blood, CD34/CD36 sorted cells were cultured in the presence of Erythropoietin (Epo) and Epo plus mast cell growth factor (MGF). The CD34+/CD36- cell fraction from bone marrow supported 74 +/- 33 erythroid burst forming units (BFU-E)/10(4) cells (mean +/- SD, n = 4) in the presence of Epo, which increased 2.1-fold by coculturing with MGF. However, erythroid colony-forming units (CFU-E) were not cultured from the CD34+/CD36- cell fraction. In contrast, the CD34-/CD36+ cell fraction supported CFU-Es in the presence of Epo (152 +/- 115/10(5)) or Epo plus MGF (180 +/- 112/10(5)), whereas BFU-Es were hardly noticed. However, the transition of the BFu-E to CFU-E was observed by incubating CD34+/CD36- cells (10(4)/100 microL) in suspension with Epo plus MGF for 7 days followed by Epo in the colony assay. This was reflected by the appearance of CD34-/CD36+/Glycophorin A+/CD14- cells. In addition high numbers of CFU-Es (1,000 +/- 150, n = 4) were cultured from this cell fraction. In contrast to bone marrow erythroid progenitors, no peripheral blood CFU-Es were cultured from either the CD36+ or CD36- fraction, whereas BFU-Es were predominantly present in the CD36+ fraction. However, the CD34+ progenitor cell from peripheral blood did have intrinsic capacity to differentiate to CFU-Es because CD34+/CD36- cells incubated with Epo plus MGF for 7 days and followed by Epo in the colony assay, supported high numbers of CFU-Es (1,200 +/- 400, n = 3). To study whether additional growth factors have similar effects on erythroid progenitors, experiments were performed with interleukin 1 (IL-1), IL-3, and IL-6. IL-1 and IL-6 did not modulate the Epo supported proliferation and differentiation. In contrast, IL-3 in the presence of Epo did support CFU-Es, from CD34+/CD36- cells after 7 days in suspension culture. However, flow cytometry analysis showed that Epo plus IL-3 not only supported CD34-/CD36+/Glycophorin A+ cells but also CD36+/CD14+ cells, indicating the differentiation along different cell lineages. In summary, the data show a phenotypic distinction between bone marrow and peripheral blood erythroid progenitors with regard to CD36 expression. In addition, the results suggest that Epo plus MGF or IL-3 and preincubation in suspension culture are prerequisites for the transition of the BFU-E to the CFU-E.

Antigens, CD↗

A carboxyl terminal truncation mutant of CD36 is secreted and binds thrombospondin: evidence for a single transmembrane domain.

CD36 has been implicated in several intracellular signalling events, including platelet and monocyte activation, and receptor-mediated internalization of bound ligands such as oxidized low-density lipoprotein and apoptotic neutrophils. These processes are presumably mediated by the intracytoplasmic domain(s) of the molecule. By analysis of hydrophobicity plots and by analogy to rat LIMPII, which has a 60% homology to CD36, a two-transmembrane domain model has been proposed. To characterize the structure-function relationships of CD36 involved in transducing the signal, we have defined the number of transmembrane and intracellular domains experimentally using a mutagenesis approach. A truncated CD36 cDNA was constructed that encodes a protein that terminates just proximal to the putative C-terminal transmembrane domain. This mutant was cloned into eukaryotic expression plasmid vectors to generate short-term and stable transfected cells. Our results indicate that the truncated mutant is secreted by the transfectants into the postculture medium, indicating that there is only one transmembrane domain in CD36, which is present at the C-terminal end. The soluble secreted protein from all of these cells is functional as indicated by its binding to thrombospondin.

Amino Acid Sequence↗

CD36 is a receptor for oxidized low density lipoprotein.

The oxidation of low density lipoprotein (LDL) in the arterial wall is thought to contribute to human atherosclerotic lesion formation, in part by the high affinity uptake of oxidized LDL (OxLDL) by macrophages, resulting in foam cell formation. We have utilized cloning by expression to identify CD36 as a macrophage receptor for OxLDL. Transfection of a CD36 clone into 293 cells results in the specific and high affinity binding of OxLDL, followed by its internalization and degradation. An anti-CD36 antibody blocks 50% of the binding of OxLDL to platelets and to human macrophage-like THP cells. Furthermore, like mouse macrophages, 293 cells expressing CD36 recognize LDL which has been oxidized only 4 h, whereas more extensive oxidation of the LDL is required for recognition by the other known OxLDL receptors, the acetylated LDL (AcLDL) receptor and Fc gamma RII-B2. CD36 may play a role in scavenging LDL modified by oxidation and may mediate effects of OxLDL on monocytes and platelets in atherosclerotic lesions.

Animals↗

Platelets lacking functional CD36 (glycoprotein IV) show reduced adhesion to collagen in flowing whole blood.

A parallel-plate perfusion chamber has been used to evaluate the contribution of the adhesive membrane glycoprotein CD36 (GPIV) to platelet adhesion on type I collagen in flowing whole blood at a shear rate of 800 s-1. In one series of experiments, reconstituted normal blood (hematocrit 0.4; platelet count 1.5 x 10(5)/microL) was prepared from washed red blood cells, plasma, and washed platelets that had been incubated with Fab fragments of a monospecific polyclonal anti-CD36 antibody (50 micrograms/mL, 30 minutes, 37 degrees C). Percent surface coverage of collagen-coated coverslips using reconstituted blood with antibody-blocked platelets, as compared with paired reconstituted controls (100%), was 50% at 2 minutes, 87% at 5 minutes, and 90% at 10 minutes. Further studies were performed by perfusion of whole blood from a healthy donor of the Naka-negative phenotype, whose platelets constitutively lack CD36, over collagen-coated coverslips. In this case, percent surface coverage was 55% of normal controls at 2 minutes, 76% of controls at 5 minutes, and 72% of controls at 10 minutes. In both preparations, platelets lacking functional CD36 had a statistically significant decrease (P < .005) in adhesion after 2 minutes and 10 minutes perfusion but not at 5 minutes. These results show that functional CD36 facilitates the rapid adhesion of platelets to collagen and that this effect is seen at the earliest time points of their interaction.

Antibodies↗

[Hypertrophic cardiomyopathy showing no 123I-BMIPP myocardial accumulation with type I CD36 deficiency].

A 57 years old male consulted our hospital in complaining chest oppression and short of breath. Familial and dilated phase hypertrophic cardiomyopathy (HCM) was detected by ECG, echocardiography, left ventriculography and left ventricular endomyocardial biopsy. 201T1 SPECT showed regional increased accumulation in the ventricular septum, however, no myocardial accumulation of 123I-beta-methyl-p-iodophenylpentadecanoic acid (123I-BMIPP) was observed. We analyzed CD36 in this patient, and found he had type 1 CD36 deficiency. Myocardial uptake of long-chain fatty acids occurs via a specific transporter, which is homologous with human CD36. We hypothesize that CD36 deficiency, especially type 1 CD36 deficiency, might be one factor of no myocardial 123I-BMIPP uptake.

CD36 Antigens↗

Senescent fibroblasts drive CD8+ T cell dysfunction in colorectal cancer via CD36-mediated lipid transfer and peroxidation.

BACKGROUND: Functional exhaustion of tumor-infiltrating CD8+ T cells represents a hallmark of colorectal cancer (CRC) immunosuppression, though its mechanistic drivers remain elusive. Given the established correlation between CRC progression and stromal senescence characterized by pathological lipid accumulation and impaired immunity, we investigated whether and how senescent fibroblasts actively regulate CD8+ T cell dysfunction. METHODS: Single-cell RNA sequencing (scRNA-seq) analysis was conducted to unveil the diverse fibroblast populations and the significant lipid metabolism changes between senescent fibroblasts and non-senescent fibroblasts in human CRC specimens and adjacent normal mucosa. Machine-learning identified senescent fibroblasts with a distinct gene signature. Cell-cell communication analysis was used to evaluate the interactions between senescent fibroblasts and CD8+ T cells in colorectal cancer. Co-culture experiments were conducted among senescent fibroblasts, CD8+ T cells and patient-derived organoids of CRC (CRC-PDOs), with the results evaluated with high-content imaging and propidium iodide/Hoechst 33,342 staining. Flow cytometry, ELISA and lipid pulse-chase with BODIPY FL C16 were performed to detect the alterations of CD8+ T cell cytotoxic function and metabolic status. AOM/DSS-induced CRC mouse model was used to conduct in vivo validation to evaluate whether senolytics could suppress CRC progression. Patients from the Cancer Genome Atlas colorectal cancer cohort were stratified into CD36-high and CD36-low groups by median expression, and drug sensitivity for GDSC2 compounds was predicted computationally using the oncoPredict R package. RESULTS: ScRNA-seq demonstrated the specific cell population presence and divergence of senescent fibroblasts between neoplastic and histologically normal adjacent cell clusters in CRC. Random Forest was employed for cell senescence classification. Feature importance analysis identified five genes as key contributors to the model&#x2019;s decision process. Cell-cell communication analysis revealed enhanced interactions between senescent fibroblasts and CD8+ T cells in CRC. Co-culture of senescent fibroblasts significantly impaired the cytotoxic functions of CD8+ T cells on CRC-PDOs, which was reflected by the declined proportions of granzyme B (GZMB) + and interferon gamma (IFN&#x3b3;) + CD8+ T cells and enhanced viability of CRC-PDOs. Mechanistically, the co-culture with senescent fibroblasts promoted the lipid shuttling into CD8+ T cells to induce lipid peroxidation and downstream impairment of cytotoxicity. Furthermore, the inhibition of CD36, the specific scavenger receptor for lipid uptake of CD8+ T cells, effectively suppressed lipid transfer and peroxidation thereby preserving the effector functions of CD8+ T cells and ultimately promoting tumor apoptosis. Complementarily, in vivo senolytic treatment significantly suppressed CRC progression in AOM-DSS CRC mouse models. Top 12 therapeutic agents were identified significantly enhanced predicted efficacy in CD36-high tumors. CONCLUSIONS: Our study identified a substantial population of senescent fibroblasts in human CRC through single cell transcriptomics, machine-learning and clinical biopsies. These senescent fibroblasts impair CD8+ T cell-mediated killing of CRC-PDOs via CD36-dependent lipid transfer, suggesting senolytic targeting of stromal cells as a promising immunotherapeutic strategy for CRC.

Colorectal Neoplasms↗

Expression of CD36 (OKM5) antigen on epidermal cells in normal and diseased skin.

The expression of the CD36 (OKM5) antigen was studied with the PAP technique on sections of skin from healthy subjects and of normal and diseased skin from patients with various skin diseases. In specimens from healthy subjects the antigen was found on vascular and perivascular structures and in some cases it was seen on cells of the acrosyringium. A net-like pattern of CD36 was observed in the upper part of the stratum spinosum in skin lesions of patients with psoriasis, lichen planus, pityriasis rosea, morbilliform drug reactions, necrobiosis lipoidica, lichen amyloidosus, Darier's disease and ichthyosis vulgaris. Expression of CD36 was also seen in the nonlesional skin just below the granular layer in 3 of 5 patients with factitial urticaria with immediate dermographism, but not in delayed dermographism or chronic urticaria. In ichthyosis vulgaris CD36 was also expressed in dendritic cells of the basal layer and in a patient with a graft versus host reaction it was recognized both on scattered keratinocytes and on dendritic cells in the epidermis. The role of the expression of the CD36 antigen in the skin is unknown. The activated cells might possibly serve as antigen-presenting cells and/or have a modulatory influence on an inflammatory reaction.

Antibodies, Monoclonal↗

Bacteroides cellulosilyticus-derived 2-hydroxyphenylacetic acid rectifies hepatic lipid homeostasis in MASLD by targeting the PPAR&#x3b3;-CD36 axis.

The gut microbiota plays an important role in the occurrence and development of metabolic dysfunction-associated steatotic liver disease (MASLD), but the specific molecular mechanisms involved have not been fully elucidated. In this study, human cohort studies were performed to identify that the relative abundance of Bacteroides cellulosilyticus (B. cellulosilyticus) was significantly decreased in patients with MASLD. Through the integration of metagenomic and metabolomic analyses, it was confirmed that B. cellulosilyticus and its metabolite 2-hydroxyphenylacetic acid (2HPAA) are key factors regulating the occurrence and development of MASLD. Single-cell sequencing and lipidomic analyses revealed that 2HPAA can enter the liver through the enterohepatic circulation to exert regulatory effects. Specifically, 2HPAA inhibits the peroxisome proliferator-activated receptor &#x3b3; (PPAR&#x3b3;) signaling pathway, thereby suppressing the expression of the fatty acid transporter CD36. Meanwhile, 2HPAA regulates lipid metabolism in hepatocytes by significantly enhancing palmitate conversion efficiency and inhibiting CD36 palmitoylation. This dual regulatory effect on CD36 expression and palmitoylation can reduce lipid accumulation in hepatocytes and ultimately alleviate MASLD progression. These findings reveal the mechanism by which B. cellulosilyticus and 2HPAA alleviate MASLD by targeting the PPAR&#x3b3;-CD36 pathway. This work provides a new perspective for the study of gut microbiota-host interactions in regulating liver diseases.

PPAR gamma↗

A CD36 nonsense mutation associated with insulin resistance and familial type 2 diabetes.

Mutations in CD36 / fatty acid translocase (FAT) gene are responsible for insulin resistance in the rat but contribution to human Type 2 diabetes is unknown. A nominal evidence for linkage of familial T2D at the CD36 locus led us to identify a rare nonsense mutation c.1079T>G (p.L360X) in one Caucasian pedigree presenting with autosomal dominant diabetes. Adiponectin levels, as marker of insulin sensitivity, were found to be significantly lower in the p.L360X variant carriers compared to homozygous for wild type CD36. Furthermore, expression studies of the truncated protein showed a defective binding of acetylated-LDL. Thus, our findings suggest a possible role for CD36 in the pathogenesis of T2D associated with reduced insulin sensitivity.

Adiponectin↗

Antennal SNMPs (sensory neuron membrane proteins) of Lepidoptera define a unique family of invertebrate CD36-like proteins.

SNMP1-Apol is an antennal-specific protein of the wild silk moth Antheraea polyphemus; the protein is abundantly expressed and localized to the receptor membranes of sex-pheromone specific olfactory sensory neurons (OSNs). SNMP1-Apol is thought to function in odor detection based on its olfactory-specific expression, localization within OSNs, developmental time of expression, and apparent homology to the CD36 family of membrane-bound receptor proteins. In the current study, SNMP1-Apol homologues were identified from the moths Bombyx mori, Heliothis virescens, and Manduca sexta. These species posses antennal mRNAs encoding proteins with amino acid sequence identities ranging from 75-80%; these proteins are collectively designated SNMP1. A second M. sexta SNMP homologue, previously identified and partially sequenced [Robertson et al.: Insect Mol Biol 8:501-518, 1999] was fully sequenced and characterized. The encoded protein shares only 26-27% sequence identity with the SNMP1 proteins, and is thus designated SNMP2-Msex. The SNMP sequences were used to identify 14 and four possible homologues in Drosophila melanogaster and Caenorhabditis elegans genome databases, respectively; thus, greatly expanding CD36 family membership among the invertebrate lineages. Despite their sequence difference, SNMP1-Msex and SNMP2-Msex expression is localized to OSNs and occurs simultaneously with the onset of olfactory function. These findings suggest that SNMPs play a central role in odor detection in insects, and that the CD36 gene family is widely represented among animal phyla. The SNMPs are the only identified neuronal members of the CD36 family, and as such expand the activities of this gene family into roles influencing brain function and behavioral action.

Aging↗

CD36 is spatially associated with glycoprotein IIb-IIIa (alpha IIb beta 3) on the surface of resting platelets.

Platelet activation and aggregation induced by agonists such as thrombin are accompanied by the phosphorylation of several proteins on tyrosine. Such tyrosine phosphorylation is dependent upon activation and ligand engagement of the major integrin receptor on the surface of platelets, glycoprotein (GP) IIb-IIIa (alpha IIb beta 3), but how this is accomplished is not known. The only platelet membrane GP known to associated with non receptor tyrosine kinases is CD36 (GPIV) which forms associations with pp60Fyn, pp62Yes, and pp54/58Lyn, and antibodies directed against CD36 activate platelets in a process dependent upon GPIIb-IIIa. These and other data suggest a physical association between the two membrane GPs, IIb-IIIa and CD36. By the use of immunoprecipitation of lysates of platelets that have been surface labeled and chemically crosslinked we show here that CD36 and GPIIb-IIIa are spatially associated on the surface of resting platelets.

Antibodies, Monoclonal↗