TY - JOUR
T1 - Phosphorylation of CREB by CaM-Kinase IV activated by CaM-kinase IV kinase
AU - Enslen, Hervé
AU - Tokumitsu, Hiroshi
AU - Soderling, T. R.
PY - 1995/2/27
Y1 - 1995/2/27
N2 - Previous reports have shown that CaM-kinase IV can phosphorylate the transcription factor CREB in vitro on Ser133. Furthermore, transfected CaM-kinase IV can activate CREB-dependent transcription, but at a lower efficiency than the cAMP-kinase. In this paper we examine the kinetics and site-specificity of CREB phosphorylation in vitro by CaM-kinase IV after its phosphorylation and activation by a newly discovered brain CaM-kinase IV kinase. Our results show that activated CaM-kinase IV has the same Km (1-5 μM) for CREB phosphorylation, but the Vmax is about 30-fold higher than with non-activated CaM-kinase IV. Activated CaM-kinase IV still shows specificity for phosphorylation of Ser133, the site necessary for transactivation by CREB. It is likely that the lower efficiency of transcriptional activation by transfected CaM-kinase IV in previous studies was due to the fact that the CaM-kinase IV was not activated by CaM-kinase IV kinase.
AB - Previous reports have shown that CaM-kinase IV can phosphorylate the transcription factor CREB in vitro on Ser133. Furthermore, transfected CaM-kinase IV can activate CREB-dependent transcription, but at a lower efficiency than the cAMP-kinase. In this paper we examine the kinetics and site-specificity of CREB phosphorylation in vitro by CaM-kinase IV after its phosphorylation and activation by a newly discovered brain CaM-kinase IV kinase. Our results show that activated CaM-kinase IV has the same Km (1-5 μM) for CREB phosphorylation, but the Vmax is about 30-fold higher than with non-activated CaM-kinase IV. Activated CaM-kinase IV still shows specificity for phosphorylation of Ser133, the site necessary for transactivation by CREB. It is likely that the lower efficiency of transcriptional activation by transfected CaM-kinase IV in previous studies was due to the fact that the CaM-kinase IV was not activated by CaM-kinase IV kinase.
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U2 - 10.1006/bbrc.1995.1289
DO - 10.1006/bbrc.1995.1289
M3 - Article
C2 - 7864890
AN - SCOPUS:0028925179
SN - 0006-291X
VL - 207
SP - 1038
EP - 1043
JO - Biochemical and Biophysical Research Communications
JF - Biochemical and Biophysical Research Communications
IS - 3
ER -