Calcium‐, calcium/calmodulin‐, and calcium/phospholipid‐stimulated protein phosphorylation in the rat anterior pituitary

James C. Pryor, Scott T. Cain, Charles B. Nemeroff

Research output: Contribution to journalArticlepeer-review

Abstract

Calcium-dependent protein phosphorylation may be a critical step in the stimulated secretion of anterior pituitary hormones. We have noted the existence of a number of calcium-calcium/calmodulin-, and calcium/phospholipid-dependent phosphoproteins in the normal rat anterior pituitary. Cell extracts were prepared from anterior pituitary glands of male rats and phosphorylated with [γ32P]ATP in the presence or absence of calcium, calmodulin, and phosphatidylserine. The samples were electrophoresed on SDS-PAGE gels, autoradiographs prepared, and phosphate incorporation into specific proteins quantitated with microdensitometry. Calcium alone significantly stimulated the phosphorylation of proteins with molecular weights of 80.0-, 62.0-, 51.0-, 30.5-, and 25.0-kDa. The phosphorylation of 21.5-, 51.0-, and 80.0-kDa MW phosphoproteins was found to be phospholipid dependent. The phosphorylation of 62.0-, 51.0-, 33.0-, 30.5-, and 25.0-kDa MW phosphoproteins was found to be calcium/calmodulin kinase dependent. Calcium/calmodulin also inhibited phosphorylation of the 80.0-kDa phosphoprotein.

Original languageEnglish (US)
Pages (from-to)140-145
Number of pages6
JournalSynapse
Volume11
Issue number2
DOIs
StatePublished - Jun 1992
Externally publishedYes

Keywords

  • Anterior pituitary
  • Calcium
  • Calmodulin
  • Phospholipids
  • Protein kinase C
  • Protein phosphorylation

ASJC Scopus subject areas

  • Cellular and Molecular Neuroscience

Fingerprint Dive into the research topics of 'Calcium‐, calcium/calmodulin‐, and calcium/phospholipid‐stimulated protein phosphorylation in the rat anterior pituitary'. Together they form a unique fingerprint.

Cite this