AA Sequence
ADPKWETKNC SVSSTNANDI TQSLTGKGND SEEEMRFQEV FMEHMSNMEK RIQHILDMEA NLMDTEHFQN FSMTTDQRFN DILLQLSTLF SSVQGHGNAI DEISKSLISL NTTLLDLQLN IENLNGKIQE NTFKQQEEIS KLEERVYNVS AEIMAMKEEQ VHLEQEIKGE VKVLNNITND LRLKDWEHSQ TLRNITLIQG PPGPPGEKGD RGPTGESGPR GFPGPIGPPG LKGDRGAIGF PGSRGLPGYA GRPGNSGPKG QKGEKGSGNT LTPFTKVRLV GGSGPHEGRV EILHSGQWGT ICDDRWEVRV GQVVCRSLGY PGVQAVHKAA HFGQGTGPIW LNEVFCFGRE SSIEECKIRQ
WGTRACSHSE DAGVTCTLHH HHHH
Background
This gene encodes the class A macrophage scavenger receptors, which include three different types (1, 2, 3) generated by alternative splicing of this gene. These receptors or isoforms are macrophage-specific trimeric integral membrane glycoproteins and have been implicated in many macrophage-associated physiological and pathological processes including atherosclerosis, Alzheimer's disease, and host defense. The isoforms type 1 and type 2 are functional receptors and are able to mediate the endocytosis of modified low density lipoproteins (LDLs). The isoform type 3 does not internalize modified LDL (acetyl-LDL) despite having the domain shown to mediate this function in the types 1 and 2 isoforms. It has an altered intracellular processing and is trapped within the endoplasmic reticulum, making it unable to perform endocytosis. The isoform type 3 can inhibit the function of isoforms type 1 and type 2 when co-expressed, indicating a dominant negative effect and suggesting a mechanism for regulation of scavenger receptor activity in macrophages.
References
Dansako H., et al. (2013) PLoS Pathog. 9:E1003345.
Shigeoka M., et al. (2013) Cancer Sci. 104:1112-1119.