Phosphorylated and nonphosphorylated Prolactin isoforms.
Specific posttranslational modifications o f monomer PRL produce a number of hormone variants. This review describes the current state of knowledge for the nonphosphorylated and phosphorylated 24-kD monomer forms. Of particular interest and significance for our future understanding of PRL endocrinology are the studies showing their differential release in response to different physiologic signals and their different activities in target tissues. In at least two target tissues, the monophosphorylated variant seems to act as an antagonist to the unmodified hormone.
Walker
A M
AM
Division of Biomedical Sciences, University of California, Riverside, CA 92521, USA.