CD36/fatty acid translocase in rats: distribution, isolation from hepatocytes, and comparison with the scavenger receptor SR-B1.
The new mAb UA009 recognizes an antigen expressed by microvascular endothelium, by lymphatic endothelium, and by some epithelia in a number of organs, including the small intestine, lactating mammary gland, kidney, lung, sebaceous glands, and circumvallate papillae of the tongue. This antigen is also expressed abundantly in the splenic red pulp and marginal zone and by monocytes, macrophages, and erythrocytes (but not by platelets). Among tissues that store or metabolize fatty acids, the antigen is expressed by adipocytes, cardiomyocytes, and red skeletal muscle. Importantly, it is expressed by steroidogenic cells in the adrenal gland, testis, and ovary, whereas in the liver it is expressed by hepatocytes in a pattern that is dependent on gender and genetic background. mAb UA009 immunoprecipitated a mol wt 85-kDa surface protein from detergent extracts of hepatocytes from Dark Agouti female rats. The N-terminal amino acid sequence of this protein was identical to fatty acid translocase (FAT), the rat cluster of differentiation 36 (CD36) ortholog. The mAb also reacted with COS-7 cells transfected with cDNA encoding FAT. cDNAs encoding a CD36/FAT-like polypeptide were prepared from both liver and heart RNA by RT-PCR. The nucleotide sequences obtained from these cDNAs (Dark Agouti rats) revealed identity and 99% similarity, respectively, with the published sequences of Cd36/Fat in rats of the Wistar and Sprague-Dawley strains. The absence of the UA009 antigen in CD36/FAT-deficient SHR/N rats confirmed the identity of the UA009 antigen and CD36/FAT. We suggest that CD36/FAT might function in the liver as a sex-regulated accessory molecule, either in reverse cholesterol transport and/or in fatty acid uptake.
Zhang
Xingqi
X
The Arthritis Research Laboratory, Hanson Centre for Cancer Research, Adelaide, South Australia, Australia.
Fitzsimmons
Rebecca L
RL
Cleland
Leslie G
LG
Ey
Peter L
PL
Zannettino
Andrew C W
AC
Farmer
Elizabeth-Anne
EA
Sincock
Paul
P
Mayrhofer
Graham
G
D000818:Animals; D000911:Antibodies, Monoclonal / Q000096:biosynthesis / Q000276:immunology; D018955:CD36 Antigens / Q000378:metabolism*; D019556:COS Cells; D002521:Cercopithecus; D018076:DNA, Complementary / Q000032:analysis; D004730:Endothelium, Vascular / Q000378:metabolism; D005260:Female; D005434:Flow Cytometry; D022781:Hepatocytes / Q000201:enzymology*; D006825:Hybridomas; D007150:Immunohistochemistry; D008562:Membrane Glycoproteins / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism*; D008565:Membrane Proteins; D051379:Mice; D027361:Organic Anion Transporters / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D011971:Receptors, Immunologic / Q000276:immunology / Q000378:metabolism*; D018110:Receptors, Lipoprotein; D051116:Receptors, Scavenger; D020133:Reverse Transcriptase Polymerase Chain Reaction; D051122:Scavenger Receptors, Class B; D013047:Specific Pathogen-Free Organisms
D000911:Antibodies, Monoclonal; D018955:CD36 Antigens; D018076:DNA, Complementary; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D027361:Organic Anion Transporters; D011971:Receptors, Immunologic; D018110:Receptors, Lipoprotein; D051116:Receptors, Scavenger; C454739:Scarb1 protein, mouse; C495125:Scarb1 protein, rat; D051122:Scavenger Receptors, Class B