Osteoclasts express high levels of p60c-src, preferentially on ruffled border membranes.
Expression of p60c-src, the normal cellular counterpart of the transforming protein of Rous sarcoma virus (RSV), p60v-src, was examined in mouse and rat authentic osteoclasts and mouse osteoclast-like multinucleated cells (MNCs) formed in vitro. In co-cultures of mouse osteoblastic cells and spleen cells, the expression of p60c-src strikingly increased on day 5 in parallel with the appearance of MNCs in the presence of 1 alpha,25-dihydroxyvitamin D3 (1 alpha,25(OH)2D3). Immunohistochemical examination confirmed the high level expression of p60c-src in both mouse authentic osteoclasts and MNCs. Electron microscopic examination revealed that p60c-src was primarily localized on ruffled border membranes and vacuoles, but not on the clear zone in rat authentic osteoclasts. These results suggest that p60c-src is important in osteoclastic bone resorption.
Tanaka
S
S
Department of Biochemistry, School of Dentistry, Showa University, Tokyo, Japan.
Takahashi
N
N
Udagawa
N
N
Sasaki
T
T
Fukui
Y
Y
Kurokawa
T
T
Suda
T
T
D000818:Animals; D015153:Blotting, Western; D002117:Calcitriol / Q000494:pharmacology; D002478:Cells, Cultured; D004591:Electrophoresis, Polyacrylamide Gel; D007150:Immunohistochemistry; D007425:Intracellular Membranes / Q000378:metabolism; D051379:Mice; D016253:Microscopy, Immunoelectron; D010010:Osteoclasts / Q000378:metabolism* / Q000648:ultrastructure; D010766:Phosphorylation; D016392:Proto-Oncogene Proteins pp60(c-src) / Q000096:biosynthesis*; D051381:Rats; D017207:Rats, Sprague-Dawley
D016392:Proto-Oncogene Proteins pp60(c-src); D002117:Calcitriol