CA10 regulates neurexin heparan sulfate addition via a direct binding in the secretory pathway.
EMBO Rep
; 22(4): e51349, 2021 04 07.
Article
em En
| MEDLINE
| ID: mdl-33586859
ABSTRACT
Neurexins are presynaptic adhesion molecules that shape the molecular composition of synapses. Diversification of neurexins in numerous isoforms is believed to confer synapse-specific properties by engaging with distinct ligands. For example, a subset of neurexin molecules carry a heparan sulfate (HS) glycosaminoglycan that controls ligand binding, but how this post-translational modification is controlled is not known. Here, we observe that CA10, a ligand to neurexin in the secretory pathway, regulates neurexin-HS formation. CA10 is exclusively found on non-HS neurexin and CA10 expressed in neurons is sufficient to suppress HS addition and attenuate ligand binding and synapse formation induced by ligands known to recruit HS. This effect is mediated by a direct interaction in the secretory pathway that blocks the primary step of HS biosynthesis:
xylosylation of the serine residue. NMR reveals that CA10 engages residues on either side of the serine that can be HS-modified, suggesting that CA10 sterically blocks xylosyltransferase access in Golgi. These results suggest a mechanism for the regulation of HS on neurexins and exemplify a new mechanism to regulate site-specific glycosylations.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Moléculas de Adesão de Célula Nervosa
/
Proteínas do Tecido Nervoso
Idioma:
En
Revista:
EMBO Rep
Assunto da revista:
BIOLOGIA MOLECULAR
Ano de publicação:
2021
Tipo de documento:
Article
País de afiliação:
Suécia