background:
CASPR is a transmembrane glycoprotein of the neurexin superfamily that is highly enriched in regions of myelinated axons. The axons of myelinated nerves in the adult nervous system possess specialized subcellular structures essential for efficient and rapid action potential propagation. CASPR and the closely related molecule CASPR2, a mammalian homolog of Drosophila Neurexin IV (Nrx-IV), demarcate distinct subdomains in myelinated axons. While CASPR is present at the paranodal junctions, CASPR2 is precisely colocalized with Shaker-like K+ channels in the juxtaparanodal region. CASPR2 specifically associates with Kv1.1, Kv1.2, and their Kvbeta2 subunit. CASPR family members may play a role in the local differentiation of the axon into distinct functional subdomains.
Function:
May play a role in the formation of functional distinct domains critical for saltatory conduction of nerve impulses in myelinated nerve fibers. Seems to demarcate the juxtaparanodal region of the axo-glial junction.
Subunit:
Associates with KCNA2.
Subcellular Location:
Membrane.
Tissue Specificity:
Predominantly expressed in nervous system.
DISEASE:
Defects in CNTNAP2 are the cause of cortical dysplasia-focal epilepsy syndrome (CDFES) [MIM:610042]. Affected individuals manifest cortical dysplasia, focal epilepsy, relative macrocephaly, and diminished deep-tendon reflexes. Intractable focal seizures begin in early childhood, after which language regression, hyperactivity, impulsive and aggressive behavior, and mental retardation develop.
Genetic variations in CNTNAP2 influences susceptibility to autism type 15 (AUTS15) [MIM:612100]. Autism is a neurodevelopmental disorder characterized by disturbance in language, perception and socialization. The disorder is classically defined by a triad of limited or absent verbal communication, a lack of reciprocal social interaction or responsiveness, and restricted, stereotypical, and ritualized patterns of interests and behavior.
Note=A chromosomal aberration involving CNTNAP2 is found in a patient with autism spectrum disorder. Paracentric inversion 46,XY,inv(7)(q11.22;q35). The inversion breakpoints disrupt the genes AUTS2 and CNTNAP2.
Similarity:
Belongs to the neurexin family.
Contains 2 EGF-like domains.
Contains 1 F5/8 type C domain.
Contains 1 fibrinogen SLCterminal domain.
Contains 4 laminin G-like domains.
Database links:
UniProtKB/Swiss-Prot: Q9UHC6.1
Important Note:
This product as supplied is intended for research use only, not for use in human, therapeutic or diagnostic applications.
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