In molecular biology, the protein domain TCP is actually a family of transcription factors named after: teosinte branched 1 (tb1, Zea mays (Maize)),[1] cycloidea (cyc) (Antirrhinum majus) (Garden snapdragon)[2] and PCF in rice (Oryza sativa).
[3] Members of the TCP protein domain family appear to be involved in cell proliferation.
They can be divided into two groups, TCP-C and TCP-P, that appear to have separated following an early gene duplication event.
[4] 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.
One of the conserved regions is predicted to form a non-canonical basic-Helix-Loop-Helix (bHLH) structure.