scholarly journals Casein kinase II enhances the DNA binding activity of serum response factor.

1990 ◽  
Vol 4 (6) ◽  
pp. 955-967 ◽  
Author(s):  
J R Manak ◽  
N de Bisschop ◽  
R M Kris ◽  
R Prywes
Keyword(s):  
Dna Binding ◽  
Serum Response Factor ◽  
Casein Kinase Ii ◽  
Binding Activity ◽  
Casein Kinase ◽  
Response Factor ◽  
Dna Binding Activity ◽  
Serum Response

Mutation of serum response factor phosphorylation sites and the mechanism by which its DNA-binding activity is increased by casein kinase II

1991 ◽  
Vol 11 (7) ◽  
pp. 3652-3659
Author(s):  
J R Manak ◽  
R Prywes
Keyword(s):  
Dna Binding ◽  
Serum Response Factor ◽  
Casein Kinase Ii ◽  
Binding Activity ◽  
Casein Kinase ◽  
Binding Domain ◽  
Response Factor ◽  
Dna Binding Domain ◽  
Dna Binding Activity ◽  
Serum Response

Casein kinase II (CKII) phosphorylates the mammalian transcription factor serum response factor (SRF) on a serine residue(s) located within a region of the protein spanning amino acids 70 to 92, thereby enhancing its DNA-binding activity in vitro. We report here that serine 83 appears to be the residue phosphorylated by CKII but that three other serines in this region can also be involved in phosphorylation and the enhancement of DNA-binding activity. A mutant that contained glutamate residues in place of these serines had only low-level binding activity; however, when the serines were replaced with glutamates and further mutations were made that increased the negative charge of the region, the resulting mutant showed a constitutively high level of binding equal to that achieved by phosphorylation of wild-type SRF. We have investigated the mechanism by which phosphorylation of SRF increases its DNA-binding activity. We have ruled out the possibilities that phosphorylation affects SRF dimerization or relieves inhibition due to masking of the DNA-binding domain by an amino-terminal region of the protein. Rather, using partial proteolysis to probe SRF's structure, we find that the conformation of SRF's DNA-binding domain is altered by phosphorylation.

scholarly journals Mutation of serum response factor phosphorylation sites and the mechanism by which its DNA-binding activity is increased by casein kinase II.

1991 ◽  
Vol 11 (7) ◽  
pp. 3652-3659 ◽  
Author(s):  
J R Manak ◽  
R Prywes
Keyword(s):  
Dna Binding ◽  
Serum Response Factor ◽  
Casein Kinase Ii ◽  
Binding Activity ◽  
Casein Kinase ◽  
Binding Domain ◽  
Response Factor ◽  
Dna Binding Domain ◽  
Dna Binding Activity ◽  
Serum Response

Casein kinase II (CKII) phosphorylates the mammalian transcription factor serum response factor (SRF) on a serine residue(s) located within a region of the protein spanning amino acids 70 to 92, thereby enhancing its DNA-binding activity in vitro. We report here that serine 83 appears to be the residue phosphorylated by CKII but that three other serines in this region can also be involved in phosphorylation and the enhancement of DNA-binding activity. A mutant that contained glutamate residues in place of these serines had only low-level binding activity; however, when the serines were replaced with glutamates and further mutations were made that increased the negative charge of the region, the resulting mutant showed a constitutively high level of binding equal to that achieved by phosphorylation of wild-type SRF. We have investigated the mechanism by which phosphorylation of SRF increases its DNA-binding activity. We have ruled out the possibilities that phosphorylation affects SRF dimerization or relieves inhibition due to masking of the DNA-binding domain by an amino-terminal region of the protein. Rather, using partial proteolysis to probe SRF's structure, we find that the conformation of SRF's DNA-binding domain is altered by phosphorylation.

scholarly journals Recruitment of the tinman homolog Nkx-2.5 by serum response factor activates cardiac alpha-actin gene transcription.

1996 ◽  
Vol 16 (11) ◽  
pp. 6372-6384 ◽  
Author(s):  
C Y Chen ◽  
R J Schwartz
Keyword(s):  
Dna Binding ◽  
Serum Response Factor ◽  
Binding Activity ◽  
Dominant Negative ◽  
Actin Gene ◽  
Response Factor ◽  
Dna Binding Activity ◽  
Actin Promoter ◽  
Alpha Actin ◽  
Serum Response

We recently showed that the cardiogenic homeodomain factor Nkx-2.5 served as a positive acting accessory factor for serum response factor (SRF) and that together they provided strong transcriptional activation of the cardiac alpha-actin promoter, depending upon intact serum response elements (SREs) (C. Y. Chen, J. Croissant, M. Majesky, S. Topouz, T. McQuinn, M. J. Frankovsky, and R. J. Schwartz, Dev. Genet. 19:119-130, 1996). As shown here, Nkx-2.5 and SRF collaborated to activate the endogenous murine cardiac alpha-actin gene in 10T1/2 fibroblasts by a mechanism in which SRF recruited Nkx-2.5 to the alpha-actin promoter. Activation of a truncated promoter consisting of the proximal alpha-actin SRE1 occurred even when Nkx-2.5 DNA-binding activity was blocked by a point mutation in the third helix of its homeodomain. Investigation of protein-protein interactions showed that Nkx-2.5 was bound to SRF in the absence of DNA in soluble protein complexes retrieved from cardiac myocyte nuclei but could also be detected in coassociated binding complexes on the proximal SRE1. Recruitment of Nkx-2.5 to an SRE depended upon SRF DNA-binding activity and was blocked by the dominant negative SRFpm1 mutant, which allowed for dimerization of SRF monomers but prevented DNA binding. Interactive regions shared by Nkx-2.5 and SRF were mapped to N-terminal/helix I and helix II/helix III regions of the Nkx-2.5 homeodomain and to the N-terminal extension of the MADS box. Our study suggests that physical association between Nkx-2.5 and SRF is one way that cardiac specified genes are activated in cardiac cell lineages.

Human and Drosophila Homeodomain Proteins That Enhance the DNA-Binding Activity of Serum Response Factor

Science ◽  
1992 ◽  
Vol 257 (5073) ◽  
pp. 1089-1095 ◽  
Author(s):  
D. A. Grueneberg ◽  
S. Natesan ◽  
C. Alexandre ◽  
M. Z. Gilman
Keyword(s):  
Dna Binding ◽  
Serum Response Factor ◽  
Binding Activity ◽  
Response Factor ◽  
Homeodomain Proteins ◽  
Dna Binding Activity ◽  
Serum Response

Nuclear import of serum response factor (SRF) requires a short amino-terminal nuclear localization sequence and is independent of the casein kinase II phosphorylation site

1994 ◽  
Vol 107 (11) ◽  
pp. 3029-3036
Author(s):  
J. Rech ◽  
I. Barlat ◽  
J.L. Veyrune ◽  
A. Vie ◽  
J.M. Blanchard
Keyword(s):  
Amino Acids ◽  
Nuclear Localization ◽  
Serum Response Factor ◽  
Phosphorylation Site ◽  
Casein Kinase Ii ◽  
Casein Kinase ◽  
Resting Cells ◽  
Response Factor ◽  
Amino Terminal ◽  
Serum Response

Serum stimulation of resting cells is mediated at least in part at the transcriptional level by the activation of numerous genes among which c-fos constitutes a model. Serum response factor (SRF) forms a ternary complex at the c-fos serum response element (SRE) with an accessory protein p62TCF/Elk-1. Both proteins are the targets of multiple phosphorylation events and their role is still unknown in the amino terminus of SRF. While the transcriptional activation domain has been mapped between amino acids 339 and 508, the DNA-binding and the dimerization domains have been mapped to between amino acids 133–235 and 168–235, respectively, no role has been proposed for the amino-terminal portion of the molecule. We demonstrate in the present work that amino acids 95 to 100 contain a stretch of basic amino acids that are sufficient to target a reporter protein to the nucleus. Moreover, this sequence appears to be the only nuclear localization signal operating in SRF. Finally, whereas the global structure around this putative nuclear location signal is reminiscent of what is found in the SV40 T antigen, the casein kinase II phosphorylation site does not determine the rate of cyto-nuclear protein transport of this protein.

scholarly journals Casein kinase II phosphorylation increases the rate of serum response factor-binding site exchange.

1992 ◽  
Vol 11 (1) ◽  
pp. 97-105 ◽  
Author(s):  
R.M. Marais ◽  
J.J. Hsuan ◽  
C. McGuigan ◽  
J. Wynne ◽  
R. Treisman
Keyword(s):  
Binding Site ◽  
Serum Response Factor ◽  
Casein Kinase Ii ◽  
Casein Kinase ◽  
Response Factor ◽  
Factor Binding Site ◽  
Factor Binding ◽  
Site Exchange ◽  
Serum Response

DNA binding activity of casein kinase II

1990 ◽  
Vol 173 (3) ◽  
pp. 862-871 ◽  
Author(s):  
Odile Filhol ◽  
Claude Cochet ◽  
Edmond M. Chambaz
Keyword(s):  
Dna Binding ◽  
Casein Kinase Ii ◽  
Binding Activity ◽  
Casein Kinase ◽  
Dna Binding Activity

scholarly journals Casein Kinase II-mediated Phosphorylation of the C Terminus of Sp1 Decreases Its DNA Binding Activity

1997 ◽  
Vol 272 (21) ◽  
pp. 13489-13495 ◽  
Author(s):  
Susan A. Armstrong ◽  
Denise A. Barry ◽  
Robert W. Leggett ◽  
Christopher R. Mueller
Keyword(s):  
Dna Binding ◽  
Casein Kinase Ii ◽  
Binding Activity ◽  
Casein Kinase ◽  
Dna Binding Activity ◽  
C Terminus
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