Suppression of growth-associated phosphorylation of proteins of fibroblasts by collagen fibrils.
Collagen fibrils suppressed serum- or epidermal growth factor (EGF)-inducible DNA synthesis of human fibroblasts. The phosphorylation of cellular proteins upon these mitogenic stimulation was analyzed by two-dimensional polyacrylamide gel electrophoresis in order to reveal a possible interference of collagen fibrils with the cellular mitogenic signal transduction pathway coupled with the protein phosphorylation-dephosphorylation reaction. Spots of phosphorylated proteins numbered 192 on plain plastic which were reduced to 143 on collagen fibrils. More than half of them were matched between the two substrates, most of which were much more weakly phosphorylated on collagen fibrils. EGF stimulated the phosphorylation of these proteins of cells on plastic. Among them a protein with an approximate molecular weight of 27K and an isoelectric point of 5.3 was early and highly responsive to EGF, phosphorylation of which seemed to be catalyzed mainly by protein kinase C and tyrosine kinase. Collagen fibrils significantly suppressed this phosphorylation. The present study demonstrates that collagen fibrils modulate the growth-associated protein phosphorylation of cells, which seems to lead to the suppression of DNA synthesis.
Koseki
N
N
Department of Biological Science, Faculty of Science, Hiroshima University, Japan.
Sato
H
H
Yoshizato
K
K
D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine / Q000494:pharmacology; D001769:Blood; D002455:Cell Division / Q000187:drug effects*; D003094:Collagen / Q000494:pharmacology*; D004247:DNA / Q000096:biosynthesis; D015180:Electrophoresis, Gel, Two-Dimensional; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004815:Epidermal Growth Factor / Q000494:pharmacology; D005347:Fibroblasts; D019833:Genistein; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007091:Image Processing, Computer-Assisted; D007529:Isoflavones / Q000494:pharmacology; D008970:Molecular Weight; D010449:Peptide Mapping; D010750:Phosphoproteins / Q000737:chemistry / Q000378:metabolism*; D010766:Phosphorylation / Q000187:drug effects; D010969:Plastics; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000502:physiology; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors / Q000502:physiology; D015398:Signal Transduction / Q000502:physiology; D012867:Skin
D004791:Enzyme Inhibitors; D007529:Isoflavones; D010750:Phosphoproteins; D010969:Plastics; D004815:Epidermal Growth Factor; D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D003094:Collagen; D004247:DNA; D019833:Genistein; D011505:Protein-Tyrosine Kinases; D011493:Protein Kinase C