Identification of a human CD36 isoform produced by exon skipping. Conservation of exon organization and pre-mRNA splicing patterns with a CD36 gene family member, CLA-1.
During an examination of different cell types for CD36 mRNA splice variants, a partial cDNA from HEL cells was isolated and characterized. This CD36 cDNA had a 309-base pair deletion following the region encoding the first putative transmembrane domain of CD36. The open reading frame of the deleted CD36 cDNA was retained and was predicted to yield a protein lacking 103 amino acid residues. The presence of this variant was confirmed in RNA pools from placental tissue by a reverse transcriptase-coupled polymerase chain reaction assay. Comparison of the HEL CD36 cDNA with the genomic sequence revealed that the mRNA represented by this variant CD36 cDNA was produced by a pre-mRNA splicing reaction that excluded exons 4 and 5. Transient expression of the variant CD36 cDNA in COS-1 cells showed that CD36 immunoreactive protein was expressed on the cell surface but lacked an antigenic epitope defined by amino acid residues 41-143. This cell surface glycoprotein (M(r) approximately 57,000) was of identical molecular weight as a CD36 isoform observed on the surface of HEL cells. The exclusion of exons during CD36 pre-mRNA processing appears to be conserved within one other CD36 gene family member, CLA-1.
Tang
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Y
Cell Biology Department, J. H. Holland Laboratory, American Red Cross, Rockville, Maryland 20855.
Taylor
K T
KT
Sobieski
D A
DA
Medved
E S
ES
Lipsky
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RH
D000595:Amino Acid Sequence; D000818:Animals; D015703:Antigens, CD / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D018955:CD36 Antigens; D002460:Cell Line; D018076:DNA, Complementary; D005091:Exons; D000882:Haplorhini; D006801:Humans; D008969:Molecular Sequence Data; D010980:Platelet Membrane Glycoproteins / Q000235:genetics*; D012322:RNA Precursors / Q000378:metabolism*; D012326:RNA Splicing; D012333:RNA, Messenger / Q000378:metabolism; D011971:Receptors, Immunologic; D018110:Receptors, Lipoprotein; D051116:Receptors, Scavenger; D051122:Scavenger Receptors, Class B; D017384:Sequence Deletion; D014407:Tumor Cells, Cultured
D015703:Antigens, CD; D018955:CD36 Antigens; D018076:DNA, Complementary; D010980:Platelet Membrane Glycoproteins; D012322:RNA Precursors; D012333:RNA, Messenger; D011971:Receptors, Immunologic; D018110:Receptors, Lipoprotein; D051116:Receptors, Scavenger; C495124:SCARB1 protein, human; D051122:Scavenger Receptors, Class B