P-type ATPases are integral membrane proteins that use the free energy of A
TP hydrolysis to generate transmembrane electrochemical ion gradients to su
pport a variety of cellular processes. They have eight signature motifs, ei
ght or ten transmembrane domains, highly conserved phosphorylation and ATP-
binding sites, and similar hydropathic profiles. This review summarizes rec
ent insights in the relationship of P-type ATPases to successful reproducti
on. and the hormone dependence of some family members. Because protein topo
logy is central to understanding the pump action of this family of enzymes,
this review also describes the dramatic change in the primary structure of
one family member that may mediate transcription in the uterus. (C) 2001 E
lsevier Science Ireland Ltd. All rights reserved.