CASPR also known as Contactin associated protein 1, Paranodin and CASPR1 is a
protein that in humans is encoded by the CNTNAP1
gene.
CASPR is a part of the
neurexin family of proteins, hence its another name "Neurexin IV". CASPR is a membrane protein found in the neuronal membrane in the
paranodal section of the axon
in
myelinated neurons, between the
Nodes of Ranvier containing Na+ channels, and
juxtaparanode, which contains K+ channels.
During myelination, caspr associates with contactin in a ''cis'' complex,
though its precise role in myelination is not yet understood.
Function
The gene product was initially identified as a 190-kD protein associated with the contactin-PTPRZ1 complex. The 1,384-
amino acid protein, also designated p190 or CASPR for 'contactin-associated protein,' includes an extracellular domain with several putative protein-protein interaction domains, a putative transmembrane domain, and a 74-amino acid
cytoplasmic
In cell biology, the cytoplasm is all of the material within a eukaryotic cell, enclosed by the cell membrane, except for the cell nucleus. The material inside the nucleus and contained within the nuclear membrane is termed the nucleoplasm. Th ...
domain.
Northern blot analysis showed that the gene is transcribed predominantly in brain as a transcript of 6.2 kb, with weak expression in several other tissues tested. The architecture of its extracellular domain is similar to that of
neurexins, and this protein may be the signaling subunit of contactin, enabling recruitment and activation of intracellular signaling pathways in neurons.
rovided by RefSeq, Jan 2009
Clinical
Mutations in CNTNAP1 cause
arthrogryposis multiplex congenita.
Other diseases associated with mutations in this gene include
lethal congenital contracture syndrome
Lethal congenital contracture syndrome 1 (LCCS1), also called Multiple contracture syndrome, Finnish type, is an autosomal recessive genetic disorder characterized by total immobility of a fetus, detectable at around the 13th week of pregnancy. LC ...
type 7 and
congenital hypomyelinating neuropathy
A birth defect, also known as a congenital disorder, is an abnormal condition that is present at birth regardless of its cause. Birth defects may result in disabilities that may be physical, intellectual, or developmental. The disabilities ca ...
type 3.
[Sabbagh S, Antoun S, Mégarbané A (2020) CNTNAP1 Mutations and Their Clinical Presentations: New Case Report and Systematic Review. Case Rep Med 2020:8795607. ]
References
Further reading
*
*
*
*
*
*
*
*
*
External links
*
{{gene-17-stub