背景
This gene is located within a D4Z4 repeat array in the subtelomeric region of chromosome 4q. The D4Z4 repeat is polymorphic in length; a similar D4Z4 repeat array has been identified on chromosome 10. Each D4Z4 repeat unit has an open reading frame (named DUX4) that encodes two homeoboxes; the repeat-array and ORF is conserved in other mammals. The encoded protein has been reported to function as a transcriptional activator of paired-like homeodomain transcription factor 1 (PITX1; GeneID 5307). Contraction of the macrosatellite repeat causes autosomal dominant facioscapulohumeral muscular dystrophy (FSHD). Alternative splicing results in multiple transcript variants. [provided by RefSeq, Apr 2015],
功能
function:Guanine nucleotide exchange factor (GEF) for Rap1A, Rap2A and M-Ras GTPases. Does not interact with cAMP.,PTM:Phosphorylated upon DNA damage, probably by ATM or ATR.,similarity:Contains 1 cyclic nucleotide-binding domain.,similarity:Contains 1 N-terminal Ras-GEF domain.,similarity:Contains 1 PDZ (DHR) domain.,similarity:Contains 1 Ras-associating domain.,similarity:Contains 1 Ras-GEF domain.,subcellular location:Upon binding to M-Ras, it translocates to the plasma membrane.,subunit:Interacts with the second PDZ domain of human PTP1e.,tissue specificity:Isoform 3 has highest expression levels in the brain, heart, liver, lung and placenta and is barely detectable in skeletal muscle, kidney and pancreas.,
