IQ Motif Containing Protein J (IQCJ)

IQCJ/SCHIP1 fusion gene based on its close proximity to the paracentric inversion breakpoint in chromosome 3q25-q29. IQCJ and SCHIP1, a Schwannomin-interacting protein, are adjacent genes. The deduced 654-amino acid IQCJ/SCHIP1 fusion protein incorporates the calmodulin-binding IQ motif from IQCJ and a leucine-zipper motif, two 14-3-3 protein-interaction motifs, a serine-rich region with a casein kinase I phosphorylation site, a SH3-binding domain, and 2 glu/asp-rich regions from SCHIP1. Semiquantitative RT-PCR detected an IQCJ/SCHIP1 fusion transcript and a splice variant of the fusion transcript lacking exon 1c of IQCJ in fetal brain, kidney, spleen, and skeletal muscle, while only the IQCJ/SCHIP1 splice variant was detected in fetal heart and lung. Northern blot analysis detected a 3.2-kb IQCJ/SCHIP1 transcript in various brain subregions.