Identification and partial purification of a chromatin bound calmodulin activated histone 3 kinase from calf thymus.
A calcium-calmodulin (Ca2(+)-CaM) stimulated histone H3 phosphorylating activity was identified as a component of a nuclear protein complex purified from a 150 mM NaCl extract of calf thymus chromatin. This activity bound to a CaM-Sepharose affinity column in a Ca2+ dependent manner and was eluted off the column in the presence of EGTA. Equilibrium centrifugation of the EGTA eluate on a sucrose density gradient revealed that the activity is a component of a larger complex identified at 25% sucrose. This complex consisted of two major proteins, having Mr of 65 and 75 kDa. Using [125I] CaM and the gel overlay technique it was shown that the 75 kDa protein is the major CaM binding protein in the complex.
Wakim
B T
BT
Macromolecular Laboratory, Stritch School of Medicine, Loyola University of Chicago, Maywood, Illinois 60153.
Picken
M M
MM
DeLange
R J
RJ
D000818:Animals; D002118:Calcium / Q000502:physiology; D002147:Calmodulin / Q000378:metabolism*; D002417:Cattle; D002843:Chromatin / Q000201:enzymology*; D004789:Enzyme Activation; D006657:Histones / Q000378:metabolism; D006656:Protamine Kinase / Q000302:isolation & purification*; D011494:Protein Kinases / Q000302:isolation & purification*; D013950:Thymus Gland / Q000201:enzymology
D002147:Calmodulin; D002843:Chromatin; D006657:Histones; D011494:Protein Kinases; D006656:Protamine Kinase; D002118:Calcium