| First Author | Xu X | Year | 2011 |
| Journal | J Biol Chem | Volume | 286 |
| Issue | 11 | Pages | 9677-87 |
| PubMed ID | 21220418 | Mgi Jnum | J:170653 |
| Mgi Id | MGI:4947018 | Doi | 10.1074/jbc.M110.187864 |
| Citation | Xu X, et al. (2011) The Ca2+ Channel {beta}4c Subunit Interacts with Heterochromatin Protein 1 via a PXVXL Binding Motif. J Biol Chem 286(11):9677-87 |
| abstractText | The beta subunits of voltage-gated Ca(2+) channels are best known for their roles in regulating surface expression and gating of voltage-gated Ca(2+) channel alpha(1) subunits. Recent evidence, however, indicates that these proteins have a variety of Ca(2+) channel-independent functions. For example, on the molecular level, they regulate gene expression, and on the whole animal level, they regulate early cell movements in zebrafish development. In the present study, an alternatively spliced, truncated beta4 subunit (beta4c) is identified in the human brain and shown to be highly expressed in nuclei of vestibular neurons. Pull-down assays, nuclear magnetic resonance, and isothermal titration calorimetry demonstrate that the protein interacts with the chromo shadow domain (CSD) of heterochromatin protein 1gamma. Site-directed mutagenesis reveals that the primary CSD interaction occurs through a beta4c C-terminal PXVXL consensus motif, adding the beta4c subunit to a growing PXVXL protein family with epigenetic responsibilities. These proteins have multiple nuclear functions, including transcription regulation (TIF1alpha) and nucleosome assembly (CAF1). An NMR-based two-site docking model of beta4c in complex with dimerized CSD is presented. Possible roles for the interaction are discussed. |
