Endothelial Precursor Protein B9 (EPPB9)

The B9 protein function is not known. Identification of a conserved mouse homolog and representation in the EST database indicates that this transcript does represent a gene. EPPB9 is located within the Smith-Magenis syndrome region on chromosome 17. The gene contains 22 different introns. Transcription produces 17 different mRNAs, 16 alternatively spliced variants and 1 unspliced form. There are 3 probable alternative promotors, 6 non overlapping alternative last exons and 9 validated alternative polyadenylation sites. The mRNAs appear to differ by truncation of the 5' end, truncation of the 3' end, presence or absence of 5 cassette exons, overlapping exons with different boundaries, alternative splicing or retention of 3 introns. 243 bp of this gene are antisense to spliced gene MAPK7, raising the possibility of regulated alternate expression.