first Tudor domain found in AT-rich interactive domain-containing protein ARID4 family
The family contains ARID4A and its paralog ARID4B, both of which are retinoblastoma (RB)-binding proteins that function as coactivators to enhance the androgen receptor (AR) and RB transcriptional activity, and play important roles in the AR and RB pathways to control male fertility. They also act as the leukemia and tumor suppressors involved in epigenetic regulation in leukemia and Prader-Willi/Angelman syndromes. Moreover, they associate with the mSIN3A histone deacetylase (HDAC) chromatin remodeling complex through their interaction with each other, as well as with the breast cancer associated tumor suppressor ING1 and the breast cancer metastasis suppressor BRMS1. Both ARID4A and ARID4B contain tandem Tudor domains, a PWWP domain (also known as HATH domain or RBB1NT domain), an AT-rich DNA-interacting domain (ARID, also known as BRIGHT), a chromobarrel domain, and a C-terminal R2 domain. The model corresponds to the first Tudor domain. The Tudor domain binds to proteins with dimethylated arginine or lysine residues, and may also bind methylated histone tails to facilitate protein-protein interactions.