pH Might play a role in regulating the function of paired amphipathic helices domains of human Sin3B by altering structure and thermodynamic stability
- 110 Downloads
Human Sin3B (hSin3B), a transcription regulator, is a scaffold protein that binds to different transcription factors and regulates transcription. It consists of six conserved domains that include four paired amphipathic helices (PAH 1–4), histone deacetylase interaction domain (HID), and highly conserved region (HCR). Interestingly, the PAH domains of hSin3B are significantly homologous to each other, yet each one interacts with a specific set of unique transcription factors. Though various partners interacting with hSin3B PAH domains have been characterized, there is no structural information available on the individual PAH domains of hSin3B. Here we characterize the structure and stability of different PAH domains of hSin3B at both nuclear and physiological pH values by using different optical probes. We found that the native state structure and stability of different PAH domains are different at nuclear pH where hSin3B performs its biological function. We also found that PAH2 and PAH3 behave differently at both nuclear and physiological pH in terms of native state structure and thermodynamic stability, while the structural identity of PAH1 remains unaltered at both pH values. The study indicates that the structural heterogeneity of different PAH domains might be responsible for having a unique set of interacting transcription factors.
Key wordsprotein structure thermodynamic stability circular dichroism transcription regulator scaffold protein
highly conserved region
histone deacetylase interaction domain
paired amphipathic helices domain
Unable to display preview. Download preview PDF.
- 10.Rayman, J. B., Takahashi, Y., Indjeian, V. B., Dannenberg, J.-H., Catchpole, S., Watson, R. J., te Riele, H., and Dynlacht, B. D. (2002) E2F mediates cell cycle-dependent transcriptional repression in vivo by recruitment of an HDAC1/mSin3B corepressor complex, Genes Devel., 16, 933–947.CrossRefPubMedCentralPubMedGoogle Scholar
- 18.Saluta, M., and Bell, P. A. (1998) Troubleshooting GST fusion protein expression in E. coli, Life Sci. News, 1.Google Scholar
- 20.Lakowicz, J. R. (2007) Principles of Fluorescence Spectroscopy, Springer.Google Scholar
- 29.Vega, A. V., Avila, G., and Matthews, G. (2013) Interaction between the transcriptional corepressor Sin3B and voltage-gated sodium channels modulates functional channel expression, Sci. Rep., 3.Google Scholar