title: Effects of platelet-derived growth factor on degradation, nuclear translocation of nonhistone proteins, and DNA synthesis.
abstract: Stimulation of resting normal rat kidney fibroblasts, prelabeled with [3H]leucine, by platelet-derived growth factor (PDGF) caused inhibition of cellular protein degradation and a parallel increased nuclear translocation of 3H-labeled nonhistone proteins (3H-NHP) and DNA synthesis. Nuclear translocation of these proteins was independent of protein synthesis. Fractionation of the nuclear 3H-NHP in a pH gradient of 2.5-6.5 showed that the protein fractions with a high degree of proteolysis in resting cells corresponded to the protein fractions with a high extent of translocation in stimulated cells, suggesting that degradation and translocation of these proteins may be related. PDGF inhibited cellular uptake of [3H]chloroquine, suggesting that PDGF inhibits NHP degradation via the lysosomal pathway. These observations support the hypothesis that PDGF induces NHP translocation to the nucleus by inhibiting lysosomal degradation of these proteins.
authors.affiliation: Department of Pathology, College of Medicine, University of Illinois, Chicago 60612.
authors.forename: H
authors.initials: H
authors.lastname: Polet
mesh_terms: D000818:Animals; D001692:Biological Transport; D002455:Cell Division; D002467:Cell Nucleus / Q000378:metabolism*; D002738:Chloroquine / Q000378:metabolism; D003513:Cycloheximide / Q000494:pharmacology; D004247:DNA / Q000096:biosynthesis*; D008247:Lysosomes / Q000378:metabolism; D010982:Platelet-Derived Growth Factor / Q000494:pharmacology*; D011506:Proteins / Q000378:metabolism*; D051381:Rats
chemical_list: D010982:Platelet-Derived Growth Factor; D011506:Proteins; D002738:Chloroquine; D004247:DNA; D003513:Cycloheximide