Selective ubiquitination of calmodulin by UBC4 and a putative ubiquitin protein ligase (E3) from Saccharomyces cerevisiae

FEBS Letters

Kulka, Richard G.¹  Raboy, Bilha¹  Parag, Hadas A.¹  Dimitrovsky, Deborah¹ 

[1] Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel

关键词: Ubiquitin;    Calmodulin;    UBC4;    Ubiquitin protein ligase;    Saccharomyces cerevisiae;    CaM;    calmodulin;    DTT;    dithiothreitol;    EGTA;    ethylene glycol-bis-(β-aminoethyl ether)N;    N;    N';    N'-tetraacetic acid;    PMSF;    phenylmethyl sulfonyl fluoride;   

DOI  :  10.1016/0014-5793(93)81081-A

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

A putative ubiquitin protein ligase (E3-CaM) which cooperates with UBC4 in selectively ubiquitinating calmodulin has been partially purified from Saccharomyces cerevisiae. Ca²⁺ was required for this activity and monoubiquitinated calmodulin was the main product of the reaction. The apparent K _m of E3-CaM for calmodulin was approximately 1 μM which is of the same order of magnitude as the concentration of calmodulin in yeast cells. Proteins which are good substrates for other E3s (E3α or E3-R) were not ubiquitinated by E3-CaM. Lower but significant activities of E3-CaM were observed when UBC1 replaced UBC4.

【 授权许可】

Unknown