Extracellular interaction between hCD98 and the PDZ class II domain of hCASK in intestinal epithelia.
The extracellular domain of the glycoprotein-associated integrin hCD98 protrudes into the basolateral extracellular space of the intestine and contains a PDZ class II-binding domain (GLLLRFPYAA, amino acids 520-529). Protein-protein interaction studies in vitro as well as in human colonic sections and Caco2-BBE cells have revealed that hCD98 coimmunoprecipitated with the basolateral membrane-associated guanylate kinase hCASK and that this interaction occurred in a PDZ domain-dependent manner. These novel results, which provide the first evidence for a PDZ domain-dependent interaction between a membrane protein and an extracellular protein, open a new field of investigation related to extracellular signaling in cell biology.
Yan
Yutao
Y
Division of Digestive Diseases, Department of Medicine, Emory University School of Medicine, 615 Michael Street, Atlanta, GA 30322, USA.
Vasudevan
Sona
S
Nguyen
Hang
H
Bork
Ulrich
U
Sitaraman
Shanthi
S
Merlin
Didier
D
D018938:Caco-2 Cells; D027261:Fusion Regulatory Protein-1 / Q000378:metabolism*; D051528:Guanylate Kinases / Q000378:metabolism*; D006801:Humans; D007413:Intestinal Mucosa / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism*; D017434:Protein Structure, Tertiary
D027261:Fusion Regulatory Protein-1; D008565:Membrane Proteins; C106868:CASK kinases; D051528:Guanylate Kinases