|
|
|
|||
| Home Help Feedback Subscriptions Archive Search Table of Contents | ||||
Development, Vol 110, Issue 2 505-513, Copyright © 1990 by Company of Biologists
JOURNAL ARTICLES |
RS Tuan and N Bigioni
Department of Biology, University of Pennsylvania, Philadelphia 19104.
A membrane-associated, Ca(2+)-activated, Mg(2+)-dependent ATPase activity has been identified in the mouse chorioallantoic placenta. The enzyme activity is expressed and increases as a function of gestation. Biochemical characterization shows that the enzyme is highly specific for Ca2+ and nucleotide triphosphates, with a Km of 0.97 mM [Ca2+] and a Vmax of 1.05 nmol Pi released mg-1 placental protein min-1. The mouse placental Ca(2+)-ATPase activity has a pI of approximately 6.8, and corresponds to two apparent Mr values of 118 and 150 x 10(3), based on Ferguson analysis of non-denaturing electrophoretograms. Enzyme activity is inhibited by phenothiazin (suggesting a calmodulin dependence), vanadate, erythrosin B and quercetin, but not by ouabain or levamisole. Enzyme cytohistochemistry revealed that the Ca(2+)-ATPase is localized to polyploid trophoblastic cells of the mouse inner placenta. These results suggest that the enzyme may be a functional component of transplacental calcium transport during mouse embryonic development.
This article has been cited by other articles:
![]() |
C. S. Kovacs, L. L. Chafe, M. L. Woodland, K. R. McDonald, N. J. Fudge, and P. J. Wookey Calcitropic gene expression suggests a role for the intraplacental yolk sac in maternal-fetal calcium exchange Am J Physiol Endocrinol Metab, March 1, 2002; 282(3): E721 - E732. [Abstract] [Full Text] [PDF] |
||||