PHD finger found in Transcription factor 19 (TCF-19) and similar proteins
TCF-19, also termed transcription factor SC1, was identified as a putative trans-activating factor with expression beginning at the late G1-S boundary in dividing cells. It also functions as a novel islet factor necessary for proliferation and survival in the INS-1 beta cell line. It plays an important role in susceptibility to both Type 1 Diabetes Mellitus (T1DM) and Type 2 Diabetes Mellitus (T2DM); it has been suggested that it may positively impact beta cell mass under conditions of beta cell stress and increased insulin demand. TCF-19 contains an N-terminal fork head association domain (FHA), a proline rich region, and a C-terminal plant homeodomain (PHD) finger. The FHA domain may serve as a nuclear signaling domain or as a phosphoprotein binding domain. The proline rich region is a common characteristic of trans-activating factors. The PHD finger may allow TCF-19 to interact with chromatin via methylated histone H3.