Effect of growth hormone on protein phosphorylation in isolated rat hepatocytes

Journal Article · Tue Feb 10 00:00:00 EST 1987 · Biochemistry; (United States)

DOI:https://doi.org/10.1021/bi00377a009· OSTI ID:6616975

Yamada, K; Lipson, K E; Marino, M W; Donner, D B

Hepatocytes from male rats were incubated with (/sup 32/P)P/sub i/ for 40 min at 37/sup 0/C, thereby equilibrating the cellular ATP pool with /sup 32/P. Subsequent exposure to bovine growth hormone for 10 additional min did not change the specific activity of cellular (..gamma..-/sup 32/P)ATP. Two-dimensional gel electrophoresis or chromatofocusing followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis was used to fractionate phosphoproteins solubilized from control or hormone-stimulated cells. Stimulation of hepatocytes with 5 nM growth hormone for 10 min at 37/sup 0/C affected the phosphorylation of a number of proteins including an M/sub r/ 46,000 species of pI 4.7 whose phosphorylation was augmented (2.65 +/- 0.50)-fold. A significant fraction of the maximal effect of growth hormone on phosphorylation of the M/sub r/ 46,000 species was elicited by 1-5% receptor occupancy. Bovine growth hormone, which binds to somatogenic receptors with great specificity, or recombinant human growth hormone, which is not contaminated with other hormones, affected phosphorylation of hepatic proteins similarly. The M/sub r/ 46,000 phosphoprotein was isolated in a fraction enriched in cytosol after centrifugation of cellular homogenates. Phosphorylation of the M/sub r/ 46,000 phosphoprotein was also increased (1.75 +/- 0.35)-fold and (2.15 +/- 0.50)-fold by insulin and glucagon, respectively. These observations are consistent with the possibility that selective changes in the phosphorylation state of cellular proteins may mediate growth hormone actions in cells.

• Research Organization: Cornell Univ., New York, NY
• OSTI ID: 6616975
• Journal Information: Biochemistry; (United States), Vol. 26:3
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
PROTEINS
AUTORADIOGRAPHY
PHOSPHORYLATION
STH
BIOCHEMISTRY
ATP
ELECTROPHORESIS
GLUCAGON
INSULIN
LIVER CELLS
MALES
PHOSPHORUS 32
RATS
ANIMAL CELLS
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CHEMICAL REACTIONS
CHEMISTRY
DAYS LIVING RADIOISOTOPES
HORMONES
ISOTOPES
LIGHT NUCLEI
MAMMALS
NUCLEI
NUCLEOTIDES
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
PEPTIDE HORMONES
PEPTIDES
PHOSPHORUS ISOTOPES
PITUITARY HORMONES
POLYPEPTIDES
RADIOISOTOPES
RODENTS
SOMATIC CELLS
VERTEBRATES
550601* - Medicine- Unsealed Radionuclides in Diagnostics