IQCJ–SCHIP1, a novel fusion transcript encoding a calmodulin-binding IQ motif protein

The existence of transcripts that span two adjacent, independent genes is considered rare in the human genome. This study characterizes a novel human fusion gene named IQCJ–SCHIP1. IQCJ–SCHIP1 is the longest isoform of a complex transcriptional unit that bridges two separate genes that encode distinct proteins, IQCJ, a novel IQ motif containing protein and SCHIP1, a schwannomin interacting protein that has been previously shown to interact with the Neurofibromatosis type 2 (NF2) protein. IQCJ–SCHIP1 is located on the chromosome 3q25 and comprises a 1692-bp transcript encompassing 11 exons spanning 828 kb of the genomic DNA. We show that IQCJ–SCHIP1 mRNA is highly expressed in the brain. Protein encoded by the IQCJ–SCHIP1 gene was localized to cytoplasm and actin-rich regions and in differentiated PC12 cells was also seen in neurite extensions.