TY - JOUR
T1 - Evidence that type II insulin-like growth factor receptor is coupled to calcium gating system
AU - Kojima, Itaru
AU - Nishimoto, Ikuo
AU - Iiri, Taroh
AU - Ogata, Etsuro
AU - Rosenfeld, Ron
N1 - Funding Information:
Acknowledgments Authors are grateful to Dr. Peter Nissley of National Institute of Health for his generous gift of highly purified rat IGF-II. We thank for MS Akiko Kojima for her secretarial assistance. The present work was supported by grants from The Ministry of Education, Science and Culture of Japan, The Research Program on Cell Calcium Signal in the Cardiovascular System, The Ichiro Kanehara Foundation, and Yamanouchi Reserch Foundation for Metabolic Disorders. This work was also supported in part by NIH grants DK28229 and 34054, andbya research award from the Diabetes and Education Foundation. Dr. Rosenfeld is the recipient of a Research Career Development Award From the NIH (DKO 01275).
PY - 1988/7/15
Y1 - 1988/7/15
N2 - In competent Balb/c 3T3 cells primed with epidermal growth factor (primed competent cells), insulin-like growth factor-II (IGF-II) stimulated calcium influx in a concentration dependent manner with the ED50 of 450 pM. When receptor-bound [125I]IGF-II was cross-linked by use of disuccinimidyl suberate, a 240 K-Da protein was radiolabeled. Excess amount of unlabeled IGF-II inhibited the affinity-labeling of the 240 K-Da protein. To further examine whether IGF-II stimulates calcium influx by acting on the type II IGF receptor, we employed polyclonal antibody raised against rat type II IGF receptor, R-II-PABl. This antibody immunoprecipitated the type II IGF receptor and inhibited IGF-II binding in Balb/c 3T3 cell membrane without affecting IGF-I binding. In primed competent cells, R-II-PABl elicited an agonistic action in stimulating [3H]thymidine incorporation. Under the same condition, R-II-PABl elicited a marked stimulation of calcium influx. These results suggest that, in Balb/c 3T3 cells, 1) relatively low concentrations of IGF-II act mainly on the type II IGF receptor; 2) the type II IGF receptor is coupled to a calcium gating system; and 3) binding of a ligand to the type II IGF receptor leads to the stimulation of DNA synthesis.
AB - In competent Balb/c 3T3 cells primed with epidermal growth factor (primed competent cells), insulin-like growth factor-II (IGF-II) stimulated calcium influx in a concentration dependent manner with the ED50 of 450 pM. When receptor-bound [125I]IGF-II was cross-linked by use of disuccinimidyl suberate, a 240 K-Da protein was radiolabeled. Excess amount of unlabeled IGF-II inhibited the affinity-labeling of the 240 K-Da protein. To further examine whether IGF-II stimulates calcium influx by acting on the type II IGF receptor, we employed polyclonal antibody raised against rat type II IGF receptor, R-II-PABl. This antibody immunoprecipitated the type II IGF receptor and inhibited IGF-II binding in Balb/c 3T3 cell membrane without affecting IGF-I binding. In primed competent cells, R-II-PABl elicited an agonistic action in stimulating [3H]thymidine incorporation. Under the same condition, R-II-PABl elicited a marked stimulation of calcium influx. These results suggest that, in Balb/c 3T3 cells, 1) relatively low concentrations of IGF-II act mainly on the type II IGF receptor; 2) the type II IGF receptor is coupled to a calcium gating system; and 3) binding of a ligand to the type II IGF receptor leads to the stimulation of DNA synthesis.
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U2 - 10.1016/0006-291X(88)90642-0
DO - 10.1016/0006-291X(88)90642-0
M3 - Article
C2 - 2456065
AN - SCOPUS:0023734810
SN - 0006-291X
VL - 154
SP - 9
EP - 19
JO - Biochemical and Biophysical Research Communications
JF - Biochemical and Biophysical Research Communications
IS - 1
ER -