在玉米黑粉菌质膜囊泡中由Ca(2 +)-ATP酶驱动的钙积累

Ca(2+)-ATPase-driven calcium accumulation in Ustilago maydis plasma membrane vesicles.

作者信息

Hernández A, Cooke D T, Clarkson D T

机构信息

Department of Agricultural Sciences, University of Bristol, AFRC Institute of Arable Crops Research, UK.

出版信息

Microbiology (Reading). 1994 Nov;140 ( Pt 11):3047-51. doi: 10.1099/13500872-140-11-3047.

DOI:10.1099/13500872-140-11-3047

PMID:7812445

Abstract

Ca2+ transport has been measured across plasma membrane vesicles isolated from cells of Ustilago maydis. This transport was found to be ATP- (or to a lesser extent GTP) and Mg(2+)-dependent. Inconsistent release of Ca2+ from intact vesicles was obtained using the calcium ionophore A23187. However, Ca2+ was released by Triton X-100 in a concentration-dependent manner. Transport was inhibited by vanadate (> 50%) and erythrosin B (about 50%), I50 being about 10 microM for both inhibitors. In the presence of the protonophores CCCP or gramicidin, partial inhibition of Ca2+ transport (about 20%) was observed, but the Ca(2+)-channel blockers, nifedipine, diltiazem and verapamil had no effect, although the latter inhibited proton transport. The results indicate that Ca2+ transport in U. maydis is regulated by a P-type ATPase with similar properties to that found in higher plants.

摘要

已对从玉米黑粉菌细胞中分离出的质膜囊泡的钙离子运输进行了测量。发现这种运输依赖于ATP（或在较小程度上依赖于GTP）和镁离子。使用钙离子载体A23187从完整囊泡中获得的钙离子释放情况不一致。然而，Triton X-100以浓度依赖的方式释放钙离子。钒酸盐（>50%）和赤藓红B（约50%）可抑制运输，两种抑制剂的半数抑制浓度（I50）约为10微摩尔。在质子载体CCCP或短杆菌肽存在的情况下，观察到钙离子运输受到部分抑制（约20%），但钙离子通道阻滞剂硝苯地平、地尔硫卓和维拉帕米没有效果，尽管后者抑制质子运输。结果表明，玉米黑粉菌中的钙离子运输由一种P型ATP酶调节，其性质与高等植物中发现的类似。