The ß2-Subunit (AMOG) of Human Na+, K+-ATPase Is a Homophilic Adhesion Molecule.
Int J Mol Sci
; 23(14)2022 Jul 14.
Article
en En
| MEDLINE
| ID: mdl-35887102
ABSTRACT
The ß2 subunit of Na+, K+-ATPase was originally identified as the adhesion molecule on glia (AMOG) that mediates the adhesion of astrocytes to neurons in the central nervous system and that is implicated in the regulation of neurite outgrowth and neuronal migration. While ß1 isoform have been shown to trans-interact in a species-specific mode with the ß1 subunit on the epithelial neighboring cell, the ß2 subunit has been shown to act as a recognition molecule on the glia. Nevertheless, none of the works have identified the binding partner of ß2 or described its adhesion mechanism. Until now, the interactions pronounced for ß2/AMOG are heterophilic cis-interactions. In the present report we designed experiments that would clarify whether ß2 is a cell-cell homophilic adhesion molecule. For this purpose, we performed protein docking analysis, cell-cell aggregation, and protein-protein interaction assays. We observed that the glycosylated extracellular domain of ß2/AMOG can make an energetically stable trans-interacting dimer. We show that CHO (Chinese Hamster Ovary) fibroblasts transfected with the human ß2 subunit become more adhesive and make large aggregates. The treatment with Tunicamycin in vivo reduced cell aggregation, suggesting the participation of N-glycans in that process. Protein-protein interaction assay in vivo with MDCK (Madin-Darby canine kidney) or CHO cells expressing a recombinant ß2 subunit show that the ß2 subunits on the cell surface of the transfected cell lines interact with each other. Overall, our results suggest that the human ß2 subunit can form trans-dimers between neighboring cells when expressed in non-astrocytic cells, such as fibroblasts (CHO) and epithelial cells (MDCK).
Palabras clave
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Moléculas de Adhesión Celular Neuronal
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Moléculas de Adhesión Celular
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Adenosina Trifosfatasas
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ATPasa Intercambiadora de Sodio-Potasio
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Proteínas de Transporte de Catión
Límite:
Animals
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Humans
Idioma:
En
Revista:
Int J Mol Sci
Año:
2022
Tipo del documento:
Article
País de afiliación:
México