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Estrogen stimulates protein tyrosine phosphorylation and Src kinase activity in avian osteoclasts
Author(s) -
Brubaker Kristen D.,
Gay Carol V.
Publication year - 2000
Publication title -
journal of cellular biochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.028
H-Index - 165
eISSN - 1097-4644
pISSN - 0730-2312
DOI - 10.1002/(sici)1097-4644(20000201)76:2<206::aid-jcb5>3.0.co;2-r
Subject(s) - proto oncogene tyrosine protein kinase src , tyrosine kinase , tyrosine protein kinase csk , tyrosine phosphorylation , cytochalasin d , chemistry , phosphorylation , estrogen , cytochalasin , microbiology and biotechnology , biology , endocrinology , biochemistry , sh2 domain , signal transduction , cell , cytoskeleton
The estrogen, 17β‐estradiol, stimulated a profound increase in phosphotyrosine immunostaining of proteins that localized along the site of attachment in avian osteoclasts within 1 min of treatment. By 10 min, this rapidly occurring event had returned to basal levels. Pretreatment with 1 μM herbimycin A, a tyrosine kinase inhibitor, prevented the response. Immunoblotting revealed that Src kinase was one of the phosphorylated intermediates. Src kinase also appeared to translocate to the periphery of the cells during the 1 min 17β‐estradiol treatment and became dispersed by 10 min. Src kinase activity measurements indicated an increase in phosphotransferase activity after the 1 min estradiol treatment; this effect diminished with longer exposures to estrogen. Pretreatment of osteoclasts with 1 μg/ml cytochalasin B, an inhibitor of actin polymerization, delayed the appearance of increased phosphotyrosine immunostaining at attachment sites, possibly through inhibition of Src kinase translocation. These findings demonstrate that estrogen stimulates rapid tyrosine phosphorylation in osteoclasts, a process that involves activation and translocation of Src kinase to the plasma membrane. J. Cell. Biochem. 76:206–216, 1999. © 1999 Wiley‐Liss, Inc.