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 very high level, 5.2 times the average gene in this release. The sequence of this gene is defined by 599 GenBank accessions from 538 cDNA clones, some from brain (seen 47 times), eye (36), placenta (24), testis (24), lung (20), uterus (20), retina (19) and 137 other tissues. We annotate structural defects or features in 15 cDNA clones.
Alternative mRNA variants and regulation: The gene contains 29 distinct introns (28 gt-ag, 1 gc-ag). Transcription produces 24 different mRNAs, 20 alternatively spliced variants and 4 unspliced forms. There are 9 probable alternative promotors, 3 non overlapping alternative last exons and 13 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 4 cassette exons, overlapping exons with different boundaries. 428 bp of this gene are antisense to spliced gene timimi, raising the possibility of regulated alternate expression.
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 dAug10).
Function: There are 17 articles specifically referring to this gene in PubMed. Functionally, the gene has been tested for association to diseases (OMIM: spastic paraplegia 20, autosomal recessive; Other sources: Disease Progression; Genetic Predisposition to Disease; Motor Neuron Disease; Multiple Sclerosis; Muscle Spasticity; Muscular Atrophy; Paraplegia; Spastic paraplegia 20, spartin (Troyer syndrome); Spastic Paraplegia, Hereditary; Syndrome; Troyer syndrome) and proposed to participate in a process (cell death). Proteins are expected to have molecular function (ubiquitin protein ligase binding) and to localize in various compartments (cytoplasm, nucleus). Putative protein interactors have been described (EPS15, SMURF2, TUBA1A, ZFYVE9).
Protein coding potential: 14 spliced and the unspliced mRNAs putatively encode good proteins, altogether 12 different isoforms (4 complete, 3 COOH complete, 5 partial), some containing MIT (microtubule interacting and transport) domain [Pfam], a coiled coil stretch [Psort2]. The remaining 9 mRNA variants (6 spliced, 3 unspliced; 6 partial) appear not to encode good proteins. Finally proteins from this gene may be modulated by acetylation; mono-methylation; 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.
Read more...