Growth hormone promoted tyrosyl phosphorylation of growth hormone receptors in murine 3T3-F442A fibroblasts and adipocytes

Journal Article · Tue Jan 12 04:00:00 EST 1988 · Biochemistry; (United States)

DOI:https://doi.org/10.1021/bi00401a049· OSTI ID:5357776

Foster, C M; Shafer, J A; Rozsa, F W; Wang, X; Lewis, S D; Renken, D A; Natale, J E; Schwartz, J; Carter-Su, C

Because many growth factor receptors are ligand-activated tyrosine protein kinases, the possibility that growth hormone (GH), a hormone implicated in human growth, promotes tyrosyl phosphorylation of its receptor was investigated. /sup 125/I-Labeled human GH was covalently cross-linked to receptors in intact 3T3-F442A fibroblasts, a cell line which differentiates into adipocytes in response to GH. The cross-linked cells were solubilized and passed over a column of phosphotyrosyl binding antibody immobilized on protein A-Sepharose. Immunoadsorbed proteins were eluted with a hapten (p-nitrophenyl phosphate) and analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and autoradiography. The eluate from the antibody column contained in M/sub r/ 134,000 /sup 125/I-GH-receptor complex. A similar result was obtained when the adipocyte form of 3T3-F442A cells was used in place of fibroblast form. O-Phosphotyrosine prevented /sup 125/I-GH-receptor complexes from binding to the antibody column, whereas O-phosphoserine and O-phosphothreonine did not. In studies of GH-promoted phosphorylation in 3T3-F442A fibroblasts labeled metabolically with (/sup 32/P)P/sub i/, GH was shown to stimulate formation of a /sup 32/P-labeled protein which bound to immobilized phosphotyrosyl binding antibodies. The molecular weight of 114,000 obtained for this protein is similar to that expected for non-cross-linked GH receptor. These observations provide strong evidence that binding of GH to its receptor stimulates phosphorylation of tyrosyl residues in the GH receptor.

• Research Organization: Univ. of Michigan Medical School, Ann Arbor
• OSTI ID: 5357776
• Journal Information: Biochemistry; (United States), Journal Name: Biochemistry; (United States) Vol. 27:1; ISSN BICHA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ADIPOSE TISSUE
AMINO ACIDS
ANIMAL CELLS
ANIMAL TISSUES
AUTORADIOGRAPHY
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BODY
CARBOXYLIC ACIDS
CHEMICAL REACTIONS
CONNECTIVE TISSUE
CONNECTIVE TISSUE CELLS
CROSS-LINKING
DAYS LIVING RADIOISOTOPES
ELECTRON CAPTURE RADIOISOTOPES
ELECTROPHORESIS
ENZYMES
FAT CELLS
FIBROBLASTS
HORMONES
HYDROXY ACIDS
INTERMEDIATE MASS NUCLEI
IODINE 125
IODINE ISOTOPES
ISOTOPES
LIGHT NUCLEI
MEMBRANE PROTEINS
MOLECULAR WEIGHT
NUCLEI
ODD-EVEN NUCLEI
ODD-ODD NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
PEPTIDE HORMONES
PHOSPHORUS 32
PHOSPHORUS ISOTOPES
PHOSPHORUS-GROUP TRANSFERASES
PHOSPHORYLATION
PHOSPHOTRANSFERASES
PITUITARY HORMONES
POLYMERIZATION
PROTEINS
RADIOISOTOPES
RECEPTORS
SOMATIC CELLS
STH
TISSUES
TRANSFERASES
TYROSINE