A CD44-like endothelial cell transmembrane glycoprotein (GP116) interacts with extracellular matrix and ankyrin.
We used complementary biochemical and immunological techniques to establish that an endothelial cell transmembrane glycoprotein, GP116, is a CD44-like molecule and binds directly both to extracellular matrix components (e.g., hyaluronic acid) and to ankyrin. The specific characteristics of GP116 are as follows: (i) GP116 can be surface labeled with Na 125I and contains a wheat germ agglutinin-binding site(s), indicating that it has an extracellular domain; (ii) GP116 displays immunological cross-reactivity with a panel of CD44 antibodies, shares some peptide similarity with CD44, and has a similar 52-kDa precursor molecule, indicating that it is a CD44-like molecule; (iii) GP116 displays specific hyaluronic acid-binding properties, indicating that it is a hyaluronic acid receptor; (iv) GP116 can be phosphorylated by endogenous protein kinase C activated by 12-O-tetradecanoylphorbol-13-acetate and by exogenously added protein kinase C; and (v) GP116 and a 20-kDa tryptic polypeptide fragment of GP116 from the intracellular domain are capable of binding the membrane-cytoskeleton linker molecule, ankyrin. Furthermore, phosphorylation of GP116 by protein kinase C significantly enhances GP116 binding to ankyrin. Together, these findings strongly suggest that phosphorylation of the transmembrane glycoprotein GP116 (a CD44-like molecule) by protein kinase C is required for effective GP116-ankyrin interaction during endothelial cell adhesion events.
Bourguignon
L Y
LY
Department of Cell Biology, School of Medicine, University of Miami, Florida 33101.
Lokeshwar
V B
VB
He
J
J
Chen
X
X
Bourguignon
G J
GJ
D000818:Animals; D017487:Ankyrins / Q000378:metabolism*; D001665:Binding Sites; D002417:Cattle; D015815:Cell Adhesion Molecules / Q000276:immunology / Q000378:metabolism*; D002460:Cell Line; D003429:Cross Reactions; D003593:Cytoplasm / Q000378:metabolism; D004730:Endothelium, Vascular / Q000166:cytology / Q000378:metabolism*; D005109:Extracellular Matrix / Q000378:metabolism*; D006820:Hyaluronic Acid / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000276:immunology / Q000378:metabolism*; D010449:Peptide Mapping; D010766:Phosphorylation; D011493:Protein Kinase C / Q000378:metabolism; D016201:Receptors, Lymphocyte Homing / Q000276:immunology / Q000378:metabolism; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D017487:Ankyrins; D015815:Cell Adhesion Molecules; D008562:Membrane Glycoproteins; D016201:Receptors, Lymphocyte Homing; D006820:Hyaluronic Acid; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate