A Receptor Linked to a Gi-Family G-Protein Functions in Initiating Oocyte Maturation in Starfish but Not Frogs

Developmental Biology

Andrew F. Giusti¹  Kathy R. Foltz¹  Rebecca R. Kalinowski¹  Laurinda A. Jaffe¹ 

[1] Department of Physiology, University of Connecticut Health Center, Farmington, Connecticut, 06032

关键词: G-protein;    receptor;    oocyte maturation;    frog;    starfish;   

DOI  :  10.1006/dbio.2002.0860

学科分类：生物科学（综合）

来源: Academic Press

【 摘 要 】

Thestimulationofoocytematurationby1-methyladenineinstarfish,andbyasteroidinfrogs,hasbeenproposedtoinvolveG-protein-coupledreceptors.ToexaminewhetheractivationofreceptorslinkedtoGiorGzwassufficienttocauseoocytematuration,weexpressedmammalianGi-andGz-linkedreceptorsinstarfishandfrogoocytes.Applicationofthecorrespondingagonistscausedmeiosistoresumeinthestarfishbutnotthefrogoocytes.WeconfirmedthatthereceptorswereeffectivelyexpressedinthefrogoocytesbyusingachimericG-protein,Gqi,thatconvertsinputfromGi-andGz-linkedreceptorstoaGqoutputandresultsinacontractionoftheoocyte'spigment.TheseresultsargueagainstGiorGzfunctioningtocausematurationinfrogoocytes.Consistently,maturation-inducingsteroidsdidnotcausepigmentcontractioninfrogoocytesexpressingGqi,andGzproteinwasnotdetectableinfrogoocytes.Forstarfishoocytes,however,ourresultssupporttheconclusionthatGifunctionsin1-methyladeninesignalingandsuggestthepossibilityofusingfrogoocytepigmentcontractionasanassaytoidentifythe1-methyladeninereceptor.Totestthisconcept,wecoexpressedGqiandastarfishadenosinereceptorinfrogoocytesandshowedthatapplyingadenosinecausedpigmentcontraction.

【 授权许可】

Unknown