CNN2
Calponin 2.
Alternative splicing results in multiple transcript variants encoding different isoforms.
Contents
Action
Thin filament-associated protein that is implicated in the regulation and modulation of smooth muscle contraction.
The interaction of calponin with actin inhibits the actomyosin Mg-ATPase activity.
It is capable of binding to actin, calmodulin, troponin C and tropomyosin.
May function in the structural organization of actin filaments.
It could play a role in smooth muscle contraction and cell adhesion.
Pathways
Cytoskeleton tension regulates the transcription of CNN2 gene and the degradation of calponin 2 protein [1].
Regulated by transcriptional factor HES-1 (hairy and enhancer of split 1) in the 5′-upstream region of mouse Cnn2 promoter (Jiang et al., 2014)[1].
Deletion or mutation of the HES-1 site in mouse Cnn2 promoter abolished the mechanical regulation and resulted in a substrate stiffness independent high level of transcriptional activity. Therefore, the regulatory mechanism is via a low tension-induced repression of transcription.
Corresponding to the down-regulation of Cnn2 gene expression, the level of HES-1 increased in cells cultured on soft gel substrates in comparison with that in cells cultured on hard gels (Jiang et al., 2014). HES-1 is known to function downstream of the Notch-RBP J signaling pathway (Kageyama et al., 1997), which has been suggested to mediate cellular mechanoregulations (Morrow et al., 2005; Morrow et al., 2007). [1].
Diseases
References
- Liu R and Jin JP. Calponin isoforms CNN1, CNN2 and CNN3: Regulators for actin cytoskeleton functions in smooth muscle and non-muscle cells. Gene. 2016 Jul 1;585(1):143-153. DOI:10.1016/j.gene.2016.02.040 |
- Shen RS, Alam A, and Zhang YX. Human liver GTP cyclohydrolase I: purification and some properties. Biochimie. 1989 Mar;71(3):343-9. DOI:10.1016/0300-9084(89)90006-0 |
Expression
Upregulated - after 1 hour after exercises.
