This family represents an N-terminal conserved region found in several huntingtin-associated protein 1 (HAP1) homologues. HAP1 binds to huntingtin in a polyglutamine repeat-length-dependent manner. However, its possible role in the pathogenesis of Huntington's disease is unclear [1-3]. This family also includes a similar N-terminal conserved region from hypothetical protein products of ALS2CR3 genes found in the human juvenile amyotrophic lateral sclerosis critical region 2q33-2q34 [4].

1: A huntingtin-associated protein enriched in brain with implications for pathology. Li XJ, Li SH, Sharp AH, Nucifora FC Jr, Schilling G, Lanahan A, Worley P, Snyder SH, Ross CA; Nature 1995;378:398-402. PMID:7477378

2: HAP1-huntingtin interactions do not contribute to the molecular pathology in Huntington's disease transgenic mice. Bertaux F, Sharp AH, Ross CA, Lehrach H, Bates GP, Wanker E; FEBS Lett 1998;426:229-232. PMID:9599014

3: Huntingtin-associated protein 1 (HAP1) binds to a Trio-like polypeptide, with a rac1 guanine nucleotide exchange factor domain. Colomer V, Engelender S, Sharp AH, Duan K, Cooper JK, Lanahan A, Lyford G, Worley P, Ross CA; Hum Mol Genet 1997;6:1519-1525. PMID:9285789

4: Cloning and characterization of three novel genes, ALS2CR1, ALS2CR2, and ALS2CR3, in the juvenile amyotrophic lateral sclerosis (ALS2) critical region at chromosome 2q33-q34: candidate genes for ALS2. Hadano S, Yanagisawa Y, Skaug J, Fichter K, Nasir J, Martindale D, Koop BF, Scherer SW, Nicholson DW, Rouleau GA, Ikeda J, Hayden MR; Genomics 2001;71:200-213. PMID:11161814