Alternative forms of the scavenger receptor BI (SR-BI).
The class B, type I scavenger receptor has been implicated as a receptor for high density lipoprotein (HDL). We have isolated a murine cDNA clone encoding an alternative form of SR-BI that differs in the putative cytoplasmic domain of the receptor. This variant form, likely the result of alternative mRNA splicing, is designated SR-BI.2. SR-BI.2 mRNA was detected in mouse tissues known to express SR-BI and tissue-specific differences in the relative abundance of SR-BI.2 were apparent. In mouse adrenal glands, SR-BI.2 represented approximately one-third of total SR-BI mRNA, whereas in mouse testes, SR-BI.2 represented the major mRNA species (79% of total). SR-BI.2 was also detected in the human cell lines examined, namely HeLa, HepG2, and THP-1 cells. CHO cells transfected with the mouse SR-BI.2 cDNA expressed significant levels of SR-BI.2 protein and acquired the ability to take up fluorescent lipid (DiI) from DiI-HDL. Alternative splicing of SR-BI represents a potentially important process for the regulation of SR-BI expression and function.
Webb
N R
NR
Department of Internal Medicine, University of Kentucky Medical Center, Lexington 40536, USA.
de Villiers
W J
WJ
Connell
P M
PM
de Beer
F C
FC
van der Westhuyzen
D R
DR
D000273:Adipose Tissue / Q000737:chemistry; D000311:Adrenal Glands / Q000737:chemistry; D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D018955:CD36 Antigens / Q000737:chemistry / Q000235:genetics*; D002460:Cell Line; D014644:Genetic Variation; D006801:Humans; D008099:Liver / Q000737:chemistry; D008297:Male; D008565:Membrane Proteins; D051379:Mice; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000032:analysis; D011971:Receptors, Immunologic; D018110:Receptors, Lipoprotein; D051116:Receptors, Scavenger; D051122:Scavenger Receptors, Class B; D013737:Testis / Q000737:chemistry; D014162:Transfection
D018955:CD36 Antigens; D008565:Membrane Proteins; D012333:RNA, Messenger; D011971:Receptors, Immunologic; D018110:Receptors, Lipoprotein; D051116:Receptors, Scavenger; C495124:SCARB1 protein, human; C454739:Scarb1 protein, mouse; D051122:Scavenger Receptors, Class B