TCP protein domain

Function

Members of the TCP protein domain family appear to be involved in cell proliferation. It may also have a role in signalling pathways since it has three phosphorylation sites. The TCP domain is necessary for specific binding to promoter elements of the Proliferating cell nuclear antigen (PCNA) gene and also in DNA binding.

Evolution

This family of transcription factors are exclusive to vascular plants. They can be divided into two groups, TCP-C and TCP-P, that appear to have separated following an early gene duplication event. This duplication event may have led to functional divergence and it has been proposed that the TCP-P subfamily are transcriptional repressors, while the TPC-C subfamily are transcription activators.

Structure

The TCP proteins code for structurally related proteins implicated in the evolution of key morphological traits. However, the biochemical function of CYC and TB1 proteins remains to be demonstrated. One of the conserved regions is predicted to form a non-canonical basic-Helix-Loop-Helix (bHLH) structure. This domain is also found in two rice DNA-binding proteins, PCF1 and PCF2, where it has been shown to be involved in DNA-binding and dimerization.

References

References

1. Finlayson SA. (May 2007). "Arabidopsis Teosinte Branched1-like 1 regulates axillary bud outgrowth and is homologous to monocot Teosinte Branched1". Plant Cell Physiol..
2. (April 1999). "The TCP domain: a motif found in proteins regulating plant growth and development". Plant J..
3. (May 2002). "DNA binding and dimerization specificity and potential targets for the TCP protein family". Plant J..
4. (July 2007). "TCP transcription factors predate the emergence of land plants". J. Mol. Evol..
5. (September 2005). "Arabidopsis TCP20 links regulation of growth and cell division control pathways". Proc. Natl. Acad. Sci. U.S.A..