Expression of Ca2+ receptors in Xenopus oocytes injected with poly(A)+ mRNA from a rat calcitonin-secreting cell line.
Poly(A)+ mRNA extracted from rat calcitonin-secreting cells (rMTC 44-2) was injected into Xenopus oocytes. In mRNA-injected oocytes the intracellular Ca2+ concentration ([Ca2+]i), measured with the Ca2+ indicator dye, fura2, increased in response to an elevation of the extracellular Ca2+ ions ([Ca2+]o). In some oocytes [Ca2+]i transiently increased in high [Ca2+]o but it did not respond to the subsequent alterations of [Ca2+]o. The addition of 10 microM carbonyl cyanide m-chlorphenylhydrazone (CCCP) to the extracellular medium restored the dependence of [Ca2+]i on [Ca2+]o in such cells. It was concluded that rMTC 44-2 cells possessed a receptor which recognizes changes in [Ca2+]o and that these receptors can be functionally expressed by microinjection of messenger RNA from rMTC 44-2 cells into Xenopus oocytes.
Department of Physiology and Pharmacology, University of California School of Medicine, Los Angeles 90024.
N
N
Yamashita
J I
JI
Schroeder
J A
JA
Umbach
C B
CB
Gundersen
D000818:Animals; D002116:Calcitonin / Q000378:metabolism*; D002118:Calcium / Q000032:analysis* / Q000378:metabolism* / Q000494:pharmacology; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone / Q000494:pharmacology; D002460:Cell Line; D016257:Fura-2; D008564:Membrane Potentials / Q000187:drug effects; D008845:Microinjections; D009865:Oocytes / Q000187:drug effects / Q000502:physiology*; D011061:Poly A / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics* / Q000378:metabolism; D051381:Rats; D011956:Receptors, Cell Surface / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D014981:Xenopus
D012333:RNA, Messenger; D011956:Receptors, Cell Surface; D011061:Poly A; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone; D002116:Calcitonin; D002118:Calcium; D016257:Fura-2