ACRC codes for a novel nuclear protein with unusual acidic repeat tract and maps to DYT3 (dystonia parkinsonism) critical interval in xq13.1

We searched for novel genes as candidates of X-linked dystonia parkinsonism (XDP) in the critical interval of Xq13.1 that harbors the disease locus (DYT3). A gene, ACRC (acidic repeat containing), was discovered by a combination of in silico and "wet" experiments. ACRC is composed of at least 12 exons and 11 introns. It is expressed in all tissues tested, including skeletal muscle, liver, kidney, pancreas, heart, lung, and brain. Highest levels of expression are found in skeletal muscle. The ACRC protein is characterized by a previously undescribed acidic repeat tract of 21 units of 8–10 amino acids. The N-terminal portion of the protein is highly acidic (pI=3.2), and the C-terminal region is basic (pI=10.2). There are nuclear localization signals in its C-terminal portion. Extensive mutation analysis of the transcribed region of the gene, including intron-exon boundaries and the 5' and 3' untranslated intervals, did not reveal a mutation in XDP patients. Exclusion of a mutation in the transcribed portion of this and all other known genes within the DYT3 critical interval suggests that XDP is most likely caused by a mutation in a regulatory region of a gene within the critical interval, or by a structural rearrangement.