periaxin (PRX, KIAA1620)

Function

• required for maintenance of peripheral nerve myelin sheath (putative)
• role in axon-glial interactions
• may interact with cytoplasmic domains of integral membrane proteins i.e. myelin-associated glycoprotein in periaxonal regions of the Schwann cell plasma membrane
• role in the early phases of myelin deposition (putative)
• interacts with SCN10A; found in a complex with SCN10A

Structure

• belongs to the periaxin family
• contains 1 PDZ (DHR) domain
• domain of repetitive pentameric units sometimes followed by a tripeptide spacer may separate two functional basic & acidic domains
• Arg/Lys-rich basic domain functions as a tripartite nuclear localization signal.

Compartment

• nucleus
• isoform 1: cell membrane associated with plasma membrane during myelination
• isoform 2: cytoplasm

Alternative splicing

named isoforms=3

Expression

• isoform 1 & 2 are found in sciatic nerve & Schwann cells

Pathology

• defects in PRX are a cause of autosomal recessive Dejerine-Sottas syndrome
• defects in PRX are the cause of Charcot-Marie-Tooth disease type 4F

More general terms

• nuclear protein
• membrane protein

Database

• OMIM: https://mirror.omim.org/entry/145900
• OMIM: https://mirror.omim.org/entry/605725
• UniProt: http://www.uniprot.org/uniprot/Q9BXM0.html