Organization of the mouse ASGR1 gene encoding the major subunit of the hepatic asialoglycoprotein receptor

The hepatic asialoglycoprotein receptor was the first of the mammalian lect ins to be recognized and has been the subject of intense investigation for three decades. Yet, the precise biological role of this major hepatic endoc ytic receptor has remained elusive. We describe here the characterization o f the mouse gene for the major subunit of this receptor (ASGR1) along with 3.5 kb of the upstream 5' region. The gene comprises eight coding exons, wi th the major transcript in liver displaying a single non-coding 5' exon. A minor hepatic transcript initiates 435 bp upstream of the major start and i ncludes an additional 5' non-coding exon and intron. A minimal 600 bp proxi mal region of ASGR1 exhibits hepatic-specific promoter activity in HepG2 ce lls in vitro. These results provide the basis for more detailed genetic stu dies on the functional role of the hepatic asialoglycoprotein receptor in m ammals. (C) 2000 Elsevier Science B.V. All rights reserved.