Insulin-like growth factor I receptor expression and function in nerve growth factor-differentiated PC12 cells.
Receptors for insulin-like growth factor I (IGF-I) were studied on PC12EY cells, a subclone of PC12. Differentiation of PC12EY cells with nerve growth factor (NGF) did not alter either the number of IGF-I receptors nor their affinity for IGF-I. IGIF-I receptors remained fully functional during differentiation, promoting increases in thymidine incorporation, glucose uptake, amino acid uptake, and the phosphorylation of the S6 protein of the ribosomes. IGF-I also increased the proportion of differentiated cells found in S-phase. But although the addition of IGF-I to naive cells caused an increase in cell number, there was no comparable increase when IGF-I was added to differentiated cells. Thus, although the receptor for IGF-I continues to be present and functional, IGF-I fails to induce cell proliferation in differentiated PC12 cells.
Yakovchenko
E
E
Section on Growth Factors, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA.
Whalin
M
M
Movsesyan
V
V
Guroff
G
G
D000596:Amino Acids / Q000378:metabolism; D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D002453:Cell Cycle / Q000187:drug effects; D002454:Cell Differentiation; D002455:Cell Division / Q000187:drug effects; D015536:Down-Regulation; D005947:Glucose / Q000378:metabolism; D007334:Insulin-Like Growth Factor I / Q000502:physiology; D009414:Nerve Growth Factors / Q000494:pharmacology; D009474:Neurons / Q000378:metabolism*; D016716:PC12 Cells; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D051381:Rats; D017526:Receptor, IGF Type 1 / Q000378:metabolism*; D038601:Ribosomal Protein S6; D019893:Ribosomal Protein S6 Kinases; D012269:Ribosomal Proteins / Q000378:metabolism
D000596:Amino Acids; D009414:Nerve Growth Factors; D038601:Ribosomal Protein S6; D012269:Ribosomal Proteins; D007334:Insulin-Like Growth Factor I; D017526:Receptor, IGF Type 1; D017346:Protein Serine-Threonine Kinases; D019893:Ribosomal Protein S6 Kinases; D005947:Glucose