THO Complex Subunit 4 (THOC4)

ALY is a ubiquitously expressed nuclear protein that specifically associates with the activation domains of LEF1 and AML1 (CBFA2). In addition, ALY can increase DNA binding by both LEF1 and AML proteins. Overexpression of ALY stimulated the activity of the TCR-alpha enhancer complex reconstituted in transfected nonlymphoid HeLa cells, whereas downregulation of ALY by antisense oligonucleotides virtually eliminated TCR-alpha enhancer activity in T cells. Similar to LEF1, ALY can stimulate transcription in the context of the TCR-alpha enhancer but apparently not when tethered to DNA through a heterologous DNA-binding domain. ALY mediates context-dependent transcriptional activation by facilitating the functional collaboration of multiple proteins in the TCR-alpha enhancer complex.