Connecting the Dots: AMOG/β₂ and Its Elusive Adhesion Partner in CNS

AMOG/β₂, the β₂ isoform of the sodium pump (Na⁺/K⁺-ATPase), functions as an adhesion molecule on glial cells, mediating critical neuron-astrocyte interactions during central nervous system (CNS) development. Despite its established role in glial adhesion, the neuronal receptor that partners with AMOG/β₂ remains unknown. This review examines the structural and functional properties of AMOG/β₂, including its capacity to form trans-dimers, both homophilic and potentially heterophilic-drawing comparisons with the β₁ subunit, a well-characterized adhesion molecule. By integrating computational modeling, in vitro data, and structural predictions, we explore how factors such as N-glycosylation and cis-membrane interactions influence β₂-mediated adhesion. We further consider candidate neuronal partners, including TSPAN31 and RTN4, and speculate on their potential roles in mediating heterophilic AMOG/β₂ interactions. Finally, we discuss the broader implications of AMOG/β₂ in neuron-glia communication, synaptic organization, neurodevelopment, and CNS disorders such as glioblastoma. Identifying the binding partner of AMOG/β₂ holds promise not only for understanding the molecular basis of CNS adhesion but also for uncovering novel mechanisms of neuroglial regulation in health and disease.