IQCJ-SCHIP1 readthrough transcript protein (IQCJ-SCHIP1)

Function

• may play a role in action potential conduction in myelinated axons through organization of molecular complexes at nodes of Ranvier & axon initial segments
• may also play arole in axon outgrowth & guidance (putative)
• Ca+2-dependent interaction (via IQ domain) with calmodulin
• interacts with ANK3 (via ANK repeats)
• required for localization at axon initial segments & nodes of Ranvier
• interacts with SPTBN4, KCNQ2 & KCNQ3 (putative)

Structure

• homooligomer (via coiled coil domain)

Compartment

• cell projection, axon, cytoplasm
• localizes to axon initial segments & nodes of Ranvier of neurons
• absent from dendrites

Alternative splicing

named isoforms=9

• IQCJ-SCHIP1-1, IQCJ-SCHIP1-2, SCHIP1-1, SCHIP1-2, SCHIP1-3, SCHIP1-4. IQCJ-1, IQCJ-2, IQCJ-3

Expression

• highly expressed in brain & to a lower extent in heart & kidney
• isoform IQCJ-SCHIP1-1 & isoform IQCJ-SCHIP1-2 are expressed in fetal brain, kidney, spleen & skeletal muscle
• isoform IQCJ-SCHIP1-2 is also detected in fetal heart & lung

Notes

• [isoform IQCJ-SCHIP1-1]: based on a naturally occurring readthrough transcript which produces an IQCJ-SCHIP1 fusion protein
• [isoform IQCJ-SCHIP1-2]: based on a naturally occurring readthrough transcript which produces an IQCJ-SCHIP1 fusion protein

More general terms

• uncharacterized protein

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=100505
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:100505
• UniProt: http://www.uniprot.org/uniprot/B3KU38.html