TY - JOUR
T1 - Gαs family G proteins activate IP3-Ca2+ signaling via Gβγ and transduce ventralizing signals in Xenopus
AU - Kume, Shoen
AU - Inoue, Takafumi
AU - Mikoshiba, Katsuhiko
PY - 2000/10/1
Y1 - 2000/10/1
N2 - During early embryonic development, IP3- Ca2+ signaling transduces ventral signaling at the time of dorsoventral axis formation. To identify molecules functioning upstream in this signal pathway, we examined effects of a panel of inhibitory antibodies against Gαq/11, Gαs/olf, or Gαi/o/t/z. While all these antibodies showed direct inhibition of their targets, their effects on redirection of the ventral mesoderm to a dorsal fate varied. Anti-Gαs/olf antibody showed strong induction of dorsal fate, anti-Gαi/o/t/z antibody did so weakly, and anti-Gαq/11 antibody was without effect. Injection of βARK, a Gβγ inhibitor, mimicked the dorsalizing effect of anti-Gαs/olf antibody, whereas injection of adenylyl cyclase inhibitors at a concentration which inhibited Gαs-coupled cAMP increase did not do so. The activation of Gαs-coupled receptor gave rise to Ca2+ transients. All these results suggest that activation of the Gαs-coupled receptor relays dorsoventral signal to Gβγ, which then stimulates PLCβ and then the IP3-Ca2+ system. This signaling pathway may play a crucial role in transducing ventral signals. (C) 2000 Academic Press.
AB - During early embryonic development, IP3- Ca2+ signaling transduces ventral signaling at the time of dorsoventral axis formation. To identify molecules functioning upstream in this signal pathway, we examined effects of a panel of inhibitory antibodies against Gαq/11, Gαs/olf, or Gαi/o/t/z. While all these antibodies showed direct inhibition of their targets, their effects on redirection of the ventral mesoderm to a dorsal fate varied. Anti-Gαs/olf antibody showed strong induction of dorsal fate, anti-Gαi/o/t/z antibody did so weakly, and anti-Gαq/11 antibody was without effect. Injection of βARK, a Gβγ inhibitor, mimicked the dorsalizing effect of anti-Gαs/olf antibody, whereas injection of adenylyl cyclase inhibitors at a concentration which inhibited Gαs-coupled cAMP increase did not do so. The activation of Gαs-coupled receptor gave rise to Ca2+ transients. All these results suggest that activation of the Gαs-coupled receptor relays dorsoventral signal to Gβγ, which then stimulates PLCβ and then the IP3-Ca2+ system. This signaling pathway may play a crucial role in transducing ventral signals. (C) 2000 Academic Press.
KW - Ca
KW - Dorsoventral axis
KW - G proteins
KW - IP
KW - Xenopus
UR - http://www.scopus.com/inward/record.url?scp=0034287453&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0034287453&partnerID=8YFLogxK
U2 - 10.1006/dbio.2000.9849
DO - 10.1006/dbio.2000.9849
M3 - Article
C2 - 10993676
AN - SCOPUS:0034287453
VL - 226
SP - 88
EP - 103
JO - Developmental Biology
JF - Developmental Biology
SN - 0012-1606
IS - 1
ER -