CaMBP-10介导的质膜H~ -ATP酶磷酸化对该酶活性的调节

CaMBP－10在活体处理条件下，抑制IAA诱导的质膜H －ATh酶活性及其磷酸化，抑制作用可被IAA逆转并在外加CaM时被消除，与前期BP－10对IAA生理应答的调节效应相吻合。并且在各项处理中，质膜H -ATh酶活性与其磷酸化水平呈现极显著的正相关。结果表明，质膜H －ATh酶活性受其磷酸化的调节，CaMBP－10参与了这一调节过程，它通过介导该酶磷酸化调节其活性，在IAA应答反应中发挥调节功能。

The Regulation of CaM BP-10 Mediated PM H~ -ATPase Activity by Phosphorylation

In preliminary Studies, it was indicated tha CaM BP10 (BP10) inhibited auxin (IAA)-induced coleopileelongaion and proto secrehon specifically, and BP10 was involved in the regulaion of the response of coleoptile to auxin.The Present study showd tha BP 10 inhibited the IAA-indued activity and phosphorylation of Plasma membrane H -ATPase (PM H -ATPase) in in vivo experiment. The inhibitory effect can be reversed by IAA and can also be overcome by the addition of CaM (Figs. 1, 2). The results are perfectly in accord with those of our Preliminary studies. The activity of PM-ATPase (Y) has been foun to be Positively correlated with the extent of its phosphorylation (X) which can be expressed as Y =22. 3303 0. 765X(P < 0. 01) (Table1, Fig. 4) These results suggest thatthe activity of PM H -ATPase is regulated by its phosphorylation and BP-10 is involved in the regulatory process. BP 10 regulats the aChvity of PM H -ATPase by edating phosphrylation of the enzym, and thereby affects cell responses to IAA.