Cyclic AMP-induced expression of steroidogenic acute regulatory protein isdependent upon phosphoprotein phosphatase activities

Citation
Pm. Jones et al., Cyclic AMP-induced expression of steroidogenic acute regulatory protein isdependent upon phosphoprotein phosphatase activities, J MOL ENDOC, 24(2), 2000, pp. 233-239
Citations number
28
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Endocrinology, Nutrition & Metabolism
Journal title
JOURNAL OF MOLECULAR ENDOCRINOLOGY
ISSN journal
0952-5041 → ACNP
Volume
24
Issue
2
Year of publication
2000
Pages
233 - 239
Database
ISI
SICI code
0952-5041(200004)24:2<233:CAEOSA>2.0.ZU;2-W
Abstract
In addition to the well-documented role of protein kinases in the regulatio n of steroid production, phosphoprotein phosphatase (PP) activity is requir ed for steroidogenesis. In the present study, we have used the mouse Y1 adr enocortical cell line to identify the site of action of PPs on steroid prod uction by measuring the effects of PP inhibition on the expression of the s teroidogenic acute regulatory (StAR) protein and on steroid production. For skolin-induced activation of cyclic AMP-dependent protein kinase (PKA) enha nced steroidogenesis and this was accompanied by an increased expression of StAR protein. Both steroidogenesis and StAR protein expression were inhibi ted by two structurally dissimilar inhibitors of PP1 and PP2A activities, o kadaic acid and calyculin A. These results suggest that inhibition of PP1 a nd PP2A inhibits steroid production by preventing the expression of the StA R protein, implicating PP1/2A dephosphorylation reactions as important regu lators of stimulus-dependent StAR protein expression, and thus of steroidog enesis.