The primary structure of the α subunit of a starfish guanosine‐nucleotide‐binding regulatory protein involved in 1‐methyladenine‐induced oocyte maturation

Kazuyoshi CHIBA, Hirohiko TADENUMA, Midori MATSUMOTO, Katsunobu TAKAHASHI, Toshiaki KATADA, Motonori HOSHI

研究成果: Article

44 引用 (Scopus)

抜粋

Starfish‐oocyte maturation induced by 1‐methyladenine (MeAde) was inhibited by microinjection of pertussis toxin (PTX). The inhibition appeared to result from PTX‐catalyzed ADP‐ribosylation of a 39‐kDa guanosine‐nucleotide‐binding regulatory protein (G protein) in the oocyte. These results strongly support the hypothesis that the MeAde‐induced signals operate via a membrane receptor and are carried by the PTX‐sensitive G protein. When PTX‐injected oocytes were treated with dithiothreitol, 85% of them reinitiated meiosis, suggesting that dithiothreitol did not act on the MeAde receptor. We constructed a cDNA library from the immature ovary of starfish, Asterina pectinifera, and screened it with the cDNA of the α subunit of an inhibitory rat G protein (Gi‐2), A positive cDNA clone contained an open reading frame of 1062 bases which had 74% identity with the rat Gi‐2 cDNA. The deduced amino acid sequence was 85% and 89% identical to rat Gi‐2 and rat Gi‐1, respectively. The α subunit of the G protein purified from cortices of starfish oocytes was digested by trypsin and the resulting four peptides were microsequenced. Comparison of these amino acid sequences with the predicted one indicated that the isolated cDNA clone encoded the α subunit of the PTX‐sensitive G protein in oocytes. The C‐terminal sequence, KNNLKDCGLF, was identical to that of Gi, suggesting that the cysteine residue is the site of ADP‐ribosylation.

元の言語English
ページ(範囲)833-838
ページ数6
ジャーナルEuropean Journal of Biochemistry
207
発行部数3
DOI
出版物ステータスPublished - 1992 8
外部発表Yes

ASJC Scopus subject areas

  • Biochemistry

フィンガープリント The primary structure of the α subunit of a starfish guanosine‐nucleotide‐binding regulatory protein involved in 1‐methyladenine‐induced oocyte maturation' の研究トピックを掘り下げます。これらはともに一意のフィンガープリントを構成します。

  • これを引用