Note that this locus is complex: it appears to produce several proteins with no sequence overlap.
Expression: According to AceView, this gene is expressed at high level, 1.4 times the average gene in this release. The sequence of this gene is defined by 166 GenBank accessions from 152 cDNA clones, some from testis (seen 40 times), skin (12), eye (7), uterus (7), brain (5), epidermis (5), melanotic melanoma (5) and 58 other tissues. We annotate structural defects or features in 5 cDNA clones.
Alternative mRNA variants and regulation: The gene contains 35 distinct gt-ag introns. Transcription produces 15 different mRNAs, 14 alternatively spliced variants and 1 unspliced form. There are 2 probable alternative promotors, 2 non overlapping alternative last exons and 5 validated alternative polyadenylation sites (see the diagram). The mRNAs appear to differ by truncation of the 5' end, truncation of the 3' end, presence or absence of 12 cassette exons, overlapping exons with different boundaries, splicing versus retention of 9 introns. 498 bp of this gene are antisense to spliced gene KCTD19, raising the possibility of regulated alternate expression.
2 variants were isolated in vivo, despite the fact that they are predicted targets of nonsense mediated mRNA decay (NMD).
Efficacy of translation may be reduced by the presence of a shorter translated product (uORF) initiating at an AUG upstream of the main open reading frame (in variant aAug10, bAug10, cAug10, hAug10).
Function: There are 11 articles specifically referring to this gene in PubMed. Functionally, the gene has been tested for association to diseases (OMIM: Spinocerebellar Ataxia 4; Spinocerebellar ataxia 31; Other sources: Cerebellar ataxia; Spinocerebellar ataxia 4, pure Japanese type; Spinocerebellar Degenerations) and proposed to participate in a process (regulation of Rho protein signal transduction). Proteins are expected to have molecular functions (guanyl-nucleotide exchange factor activity, Rho guanyl-nucleotide exchange factor activity) and to localize in intracellular. A putative protein interactor has been described (COIL).
Protein coding potential: 13 spliced and the unspliced mRNAs putatively encode good proteins, altogether 11 different isoforms (7 complete, 3 COOH complete, 1 partial), some containing domains PH domain, RhoGEF domain [Pfam], a coiled coil stretch [Psort2]. The remaining mRNA variant (spliced; partial) appears not to encode a good protein. Finally proteins from this gene may be modulated by phosphorylation; ubiquitination, as detailed at PhosphoSite.

Please quote: AceView: a comprehensive cDNA-supported gene and transcripts annotation, Genome Biology 2006, 7(Suppl 1):S12

Alternative mRNAs are shown aligned from 5' to 3' on a virtual genome where introns have been shrunk to a minimal length. Exon size is proportional to length, intron height reflects the number of cDNAs supporting each intron, the small numbers show the support of the introns in deep sequencing (with details in mouse-over) . Introns of the same color are identical, of different colors are different. 'Good proteins' are pink, partial or not-good proteins are yellow, uORFs are green. 5' cap or3' poly A flags show completeness of the transcript.
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