Alternative titles; symbols
STARS
Gene map locus
8q23TEXT
CLONING
From a differential screen for genes expressed in mouse embryonic heart, Arai et al. (2002) identified a cDNA encoding a novel actin-binding protein, designated striated muscle activator of Rho signaling (Stars). By database searching, they identified human STARS, which encodes a deduced 381-amino acid protein. Northern blot analysis revealed STARS transcripts in adult heart and skeletal muscle of both mouse and human. STARS localized to the I-band of the sarcomere in rat primary cardiomyocytes and to actin stress fibers in transfected cells. In situ hybridization experiments showed that STARS was expressed specifically in the primitive heart tube of mice at embryonic day 8.75 and also in skeletal muscle by E10.5. 
GENE FUNCTION
Using in vitro sedimentation assays, Arai et al. (2002) found that STARS directly associates with actin. Deletion mutant experiments revealed that STARS requires 2 separate but codependent regions (amino acids 234-279 and 346-375) to bind to actin.
Arai et al. (2002) found that the conserved C-terminal region of STARS was necessary and sufficient to stimulate expression from the SM22 (600818) promoter, which contains 2 serum response factor (SRF; 600589)-binding sites (CArG boxes). They also found that the transcriptional activation by STARS is mediated in large part by the cytoskeleton but also by a Rho-dependent mechanism.
Kuwahara et al. (2005) demonstrated that STARS can activate SRF by inducing the nuclear translocation of the myocardin-related transcription factors MRTFA (MKL1; 606078) and MRTFB (MKL2; 609463). The STARS-dependent nuclear import of MRTFs requires RhoA and actin polymerization, and the C-terminal actin-binding domain of STARS is necessary and sufficient for this activity. Reduction of endogenous STARS expression by use of siRNA significantly reduced SRF activity in differentiated C2C12 skeletal muscle cells and cardiac myocytes.
MAPPING
By sequence analysis, Arai et al. (2002) mapped the STARS gene to chromosome 8q23.
REFERENCES
- 1. Arai, A.; Spencer, J. A.; Olson, E. N. :
- STARS, a striated muscle activator of Rho signaling and serum response factor-dependent transcription. J. Biol. Chem. 277: 24453-24459, 2002.
PubMed ID : 11983702
- 2. Kuwahara, K.; Barrientos, T.; Pipes, G. C. T.; Li, S.; Olson, E. N. :
- Muscle-specific signaling mechanism that links actin dynamics to serum response factors. Molec. Cell. Biol. 25: 3173-3181, 2005.
PubMed ID : 15798203
CREATION DATE
Jennifer L. Goldstein : 11/30/2005
EDIT HISTORY
carol : 12/1/2005
carol : 12/1/2005
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