InterPro domain: IPR025224

Cell cycle and apoptosis regulator protein 2 (CCAR2, also known as DBC-1) regulates biological processes such as transcription, heterochromatin formation, metabolism, mRNA splicing, apoptosis, and cell proliferation [ 1 ]. It is a core component of the DBIRD complex, which affects local transcript elongation rates and alternative splicing of a large set of exons embedded in (A + T)-rich DNA regions [ 2 ]. It binds to SIRT1 and is a negative regulator of SIRT1 [ 2 ]. DBC-1 has been implicated in tumorigenesis [ 3 ].

Cell division cycle and apoptosis regulator protein 1 (CCAR1) associates with components of the Mediator and p160 coactivator complexes that play a role as intermediaries transducing regulatory signals from upstream transcriptional activator proteins to basal transcription machinery. CCAR1 also functions as a p53 coactivator and regulates expression of key proliferation-inducing genes [ 4 ].

This entry also includes protein SHORT ROOT IN SALT MEDIUM 1 from Arabidopsis. It regulates the transcription of several genes involved in the detoxification of reactive oxygen species generated by salt stress and the SOS1 gene that encodes a plasma membrane Na(+)/H(+) antiporter essential for salt tolerance [ 5 ].

1. Deleted in breast cancer 1 (DBC1) deficiency results in apoptosis of breast cancer cells through impaired responses to UV-induced DNA damage. Cancer Lett. 333, 180-6
2. DBC1 is a negative regulator of SIRT1. Nature 451, 583-6
3. p30 DBC is a potential regulator of tumorigenesis. Cell Cycle 8, 2932-5
4. CCAR1, a key regulator of mediator complex recruitment to nuclear receptor transcription complexes. Mol. Cell 31, 510-9
5. A nuclear calcium-sensing pathway is critical for gene regulation and salt stress tolerance in Arabidopsis. PLoS Genet. 9, e1003755