The MPDZ gene encodes a protein with multiple PDZ domains. These PDZ domains are protein motifs known to mediate protein-protein interactions; specifically, they interact with the C-terminal tail sequences of certain ion channel subunits and G protein-coupled receptors. The MPDZ protein is involved in cell adhesion and the viral process. It is believed to interact with HTR2C (a G-protein-coupled receptor for serotonin) and induce its clustering at the cell surface.
The gene has been implicated in Hydrocephalus, Nonsyndromic, Autosomal Recessive 2 (HYC2), a congenital communicating hydrocephalus resulting in macrocephaly, seizures and mildly decreased IQ.
The MPDZ gene is located on the short arm of chromosome 9. It spans a length of 174 kb and its coding sequence is spread across 53 exons. The protein encoded by this gene has a molecular mass of 221 kDa and contains 2070 amino acids. Alternative splicing results in multiple transcripts that encode different isoforms of the MPDZ protein. The gene is found to be expressed in the heart, brain, placenta, liver, skeletal muscle, kidney and pancreas. So far at least one homozygous mutation in the gene has been conclusively linked to HYC2: a c.628C>T transition in exon 6 of the gene resulting in a p.Q210X termination and loss of function of the MPDZ protein.