MUC17, a novel membrane-tethered mucin.
Membrane mucins have several functions in epithelial cells including cytoprotection, extravasation during metastases, maintenance of luminal structure, and signal transduction. In this paper we describe a large membrane mucin expressed in the normal intestine. This novel mucin, designated MUC17, contains an extended, repetitive extracellular glycosylation domain and a carboxyl terminus with two EGF-like domains, a SEA module domain, a transmembrane domain, and a cytoplasmic domain with potential serine and tyrosine phosphorylation sites. RNA blot analysis and in situ hybridization indicates that MUC17 is expressed in select pancreatic and colon cancer cell lines and in intestinal absorptive cells. Radiation hybrid mapping localized MUC17 to chromosome 7q22 where it resides in close proximity with three other membrane mucin genes, MUC3A, MUC3B, and MUC12. Thus, these membrane mucins reside together in a gene cluster, but are expressed in different tissues and are likely to have different functions as well.
Gum
James R
JR
Gastrointestinal Research Laboratory (151M2), Department of Veterans Affairs Medical Center, 4150 Clement Street, San Francisco, California 94121, USA. jgum@itsa.ucsf.edu
Crawley
Suzanne C
SC
Hicks
James W
JW
Szymkowski
David E
DE
Kim
Young S
YS
D000595:Amino Acid Sequence; D000818:Animals; D002897:Chromosomes, Human, Pair 7; D003001:Cloning, Molecular; D006224:Cricetinae; D005770:Gastrointestinal Neoplasms / Q000235:genetics / Q000378:metabolism; D006801:Humans; D017403:In Situ Hybridization; D007413:Intestinal Mucosa / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008969:Molecular Sequence Data; D009077:Mucins / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics*; D010802:Phylogeny; D017434:Protein Structure, Tertiary; D012333:RNA, Messenger / Q000096:biosynthesis; D021101:Radiation Hybrid Mapping; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D014018:Tissue Distribution; D014407:Tumor Cells, Cultured
C450720:MUC17 protein, human; D008562:Membrane Glycoproteins; D009077:Mucins; D012333:RNA, Messenger