This is the N-terminal domain found in hepatic lectins, also known as Asialoglycoprotein receptors (ASGRs). ASGRs function as scavengers to mediate the endocytosis of plasma glycoproteins with terminal galactose and N-acetylgalactosamine units [1,2,3]. ASGR is composed of a major (ASGR1) and a minor (ASGR2) subunits, both of which are type II, single-pass transmembrane proteins [1,2]. ASGR is highly expressed in liver but has been also identified in human peripheral blood monocytes, representing a mobile pool of the receptor reaching distant sites from the liver to play a scavenger function where there is an infection or a damaged tissue [2]. This domain includes the short, single transmembrane domain and the stalk region which mediates the oligomerisation between subunits.

1: Recognition of complex oligosaccharides by the multi-subunit asialoglycoprotein receptor. Lodish HF; Trends Biochem Sci 1991;16:374-377. PMID:1785139

2: ASGR1 and ASGR2, the Genes that Encode the Asialoglycoprotein Receptor (Ashwell Receptor), Are Expressed in Peripheral Blood Monocytes and Show Interindividual Differences in Transcript Profile. Harris RL, van den Berg CW, Bowen DJ; Mol Biol Int. 2012;2012:283974. PMID:22919488

3: Asialoglycoprotein receptor 1 mediates productive uptake of N-acetylgalactosamine-conjugated and unconjugated phosphorothioate antisense oligonucleotides into liver hepatocytes. Tanowitz M, Hettrick L, Revenko A, Kinberger GA, Prakash TP, Seth PP; Nucleic Acids Res. 2017;45:12388-12400. PMID:29069408