TY - JOUR
T1 - Regulation of phospholipase C-β3 activity by Na+/H+ exchanger regulatory factor 2
AU - Hwang, Jong Ik
AU - Heo, Kyun
AU - Shin, Kum Joo
AU - Kim, Eunjoon
AU - Yun, C. H.Chris
AU - Ryu, Sung Ho
AU - Shin, Hee Sup
AU - Suh, Pann Ghill
PY - 2000/6/2
Y1 - 2000/6/2
N2 - Among the phospholipase C that catalyzes the hydrolysis of phosphatidylinositol 4,5-bisphosphate, four mammalian phospholipase C-β (PLC-β) isotypes (isotypes 1-4) are activated through G protein-coupled receptors (GPCRs). Although the regulation of the PLC-βs by GPCRs and heterotrimeric G proteins has been extensively studied, little is known about the molecular determinants that regulate their activity. The PLC-β isozymes carry a putative PSD-95/Dlg/ZO-1 (PDZ) binding motif (X(S/T)X(V/L)COOH) at their carboxyl terminus, which is implicated in specific interactions with anchor proteins. Using the yeast two-hybrid system, we identified Na+/H+ exchanger regulatory factor 2 (NHERF2) as a protein that interacted with a C- terminal heptapeptide of PLC-β3. Immunoprecipitation studies revealed that NHERF2 interacts specifically with PLCβ3, but not with other PLC-β isotypes. Furthermore, PLC-β3 interacted with NHERF2 rather than with other PDZ-containing proteins. This interaction required the COOH-terminal NTQL sequence of PLC-β3 and the second PDZ domain of NHERF2. Interestingly, NHERF2 potentiated the PLC-β activation by carbachol in COS7 and HeLa cells, while mutant NHERF2, lacking the second PDZ domain, had no such effect. Taken together, the data suggest that NHERF2 may act as a modulator underlying the process of PLC-β3-mediated signaling.
AB - Among the phospholipase C that catalyzes the hydrolysis of phosphatidylinositol 4,5-bisphosphate, four mammalian phospholipase C-β (PLC-β) isotypes (isotypes 1-4) are activated through G protein-coupled receptors (GPCRs). Although the regulation of the PLC-βs by GPCRs and heterotrimeric G proteins has been extensively studied, little is known about the molecular determinants that regulate their activity. The PLC-β isozymes carry a putative PSD-95/Dlg/ZO-1 (PDZ) binding motif (X(S/T)X(V/L)COOH) at their carboxyl terminus, which is implicated in specific interactions with anchor proteins. Using the yeast two-hybrid system, we identified Na+/H+ exchanger regulatory factor 2 (NHERF2) as a protein that interacted with a C- terminal heptapeptide of PLC-β3. Immunoprecipitation studies revealed that NHERF2 interacts specifically with PLCβ3, but not with other PLC-β isotypes. Furthermore, PLC-β3 interacted with NHERF2 rather than with other PDZ-containing proteins. This interaction required the COOH-terminal NTQL sequence of PLC-β3 and the second PDZ domain of NHERF2. Interestingly, NHERF2 potentiated the PLC-β activation by carbachol in COS7 and HeLa cells, while mutant NHERF2, lacking the second PDZ domain, had no such effect. Taken together, the data suggest that NHERF2 may act as a modulator underlying the process of PLC-β3-mediated signaling.
UR - http://www.scopus.com/inward/record.url?scp=0034596054&partnerID=8YFLogxK
U2 - 10.1074/jbc.M001410200
DO - 10.1074/jbc.M001410200
M3 - Article
C2 - 10748023
AN - SCOPUS:0034596054
VL - 275
SP - 16632
EP - 16637
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
SN - 0021-9258
IS - 22
ER -