CNTNAP1
CNTNAP1 (contactin associated protein 1, also known as Caspr, p190, CNTNAP and NRXN4) is a neurexin-family membrane protein that marks the paranodal region of the axo-glial junction. It contributes to the organisation of myelinated axons and to signalling between axons and myelinating glia. Browse Assay Genie's current range of CNTNAP1 research reagents below, or read on for the biology behind the target.
CNTNAP1 is required, together with CNTNAP2, for the radial and longitudinal organisation of myelinated axons. It takes part in forming the functionally distinct domains that are critical for saltatory conduction of nerve impulses in myelinated nerve fibres. The protein demarcates the paranodal region of the axo-glial junction, and in association with contactin it is involved in signalling between axons and myelinating glial cells.
The CNTNAP1 protein was first identified as a 190-kD species associated with the contactin-PTPRZ1 complex, which gave rise to the names p190 and Caspr, short for 'contactin-associated protein'. It has an extracellular domain containing several putative protein-protein interaction domains, a putative transmembrane domain and a short 74-amino acid cytoplasmic domain. Its extracellular architecture resembles that of the neurexins, and UniProt places it in the neurexin family, which accounts for the alias NRXN4. Northern blot analysis showed that the CNTNAP1 gene is transcribed predominantly in brain, with weak expression in several other tissues tested.
Because of its domain organisation, CNTNAP1 may act as the signalling subunit of contactin, enabling recruitment and activation of intracellular signalling pathways in neurons. HGNC classifies it in the contactin associated protein family, alongside CNTNAP2 and CNTNAP3. These features make it a useful marker for studying paranodal junction structure and axon-glia communication.
CNTNAP1 is required, with CNTNAP2, for the radial and longitudinal organisation of myelinated axons.
The protein helps form the distinct axonal domains that are critical for saltatory conduction of nerve impulses.
CNTNAP1 demarcates the paranodal region of the axo-glial junction, making it a reference point for junction architecture.
In association with contactin, CNTNAP1 is involved in signalling between axons and myelinating glial cells.
CNTNAP1 is required, with CNTNAP2, for the radial and longitudinal organisation of myelinated axons. It supports formation of the domains needed for saltatory conduction, demarcates the paranodal axo-glial junction, and with contactin mediates signalling between axons and myelinating glial cells.
CNTNAP1 is also called Caspr, p190, CNTNAP and NRXN4. Caspr stands for 'contactin-associated protein', and p190 reflects its initial identification as a 190-kD protein associated with the contactin-PTPRZ1 complex. The name NRXN4 reflects its neurexin-like extracellular architecture.
Orthologues exist in mouse and rat, where the gene is named Cntnap1. Researchers working in these species should check the datasheet of any product for its validated reactivity.
Other contactin associated protein family members with research reagents at Assay Genie.
Gene and protein annotations from HGNC, NCBI Gene and UniProt P78357; product specifications from Assay Genie datasheets.