SATB1 (DNA-binding protein SATB1) is a crucial silencing factor that contributes to the initiation of X inactiviation mediated by Xist RNA that occurs during embryogenesis and in lymphoma. SATB1 binds to DNA at special AT-rich sequences, the consensus SATB1-binding sequence, and at nuclear matrix- or scaffold-associated regions. It is thought to recognize the sugar-phosphate structure of double-stranded DNA. SATB1 is also a transcriptonal repressor controlling nuclear and viral gene expression in a phosphorylated and acetylated status-dependent manner by binding to matrix attachment regions of DNA and inducing a local chromatin-loop remodeling. SATB1 modulates the genes that are essential in the maturatio of the immune T-cell CD8SP from thymocytes. Alu-like motifs and SATB1-binding sites provide an unique chromatin context which seems preferentially targeted by the HIV-1 integration machinery. Moreover, HIV-1 Tat may overcome SATB1-mediated repression of IL1 and IL2RA in T-cells by binding to the same domain as HDAC1.
DNA-binding protein SATB1; special AT-rich sequence binding protein 1 (binds to nuclear matrix/scaffold-associating DNA); Special AT-rich sequence-binding protein 1