Work

Na+ influx via Orai1 inhibits intracellular ATP-induced mTORC2 signaling to disrupt CD4 T cell gene expression and differentiation

Year: 2017

Type: article

Abstract: T cell effector functions require sustained calcium influx. However, the signaling and phenotypic consequences of non-specific sodium permeation via calcium channels remain unknown. α-SNAP is a crucial component of Orai1 channels, and its depletion disrupts the functional assembly of Orai1 multimers. Here we show that α-SNAP hypomorph, hydrocephalus with hopping gait, Napahyh/hyh mice harbor significant defects in CD4 T cell gene expression and Foxp3 regulatory T cell (Treg) differentiation. Mechanistically, TCR stimulation induced rapid sodium influx in Napahyh/hyh CD4 T cells, which reduced intracellular ATP, [ATP]i. Depletion of [ATP]i inhibited mTORC2 dependent NFκB activation in Napahyh/hyh cells but ablation of Orai1 restored it. Remarkably, TCR stimulation in the presence of monensin phenocopied the defects in Napahyh/hyh signaling and Treg differentiation, but not IL-2 expression. Thus, non-specific sodium influx via bonafide calcium channels disrupts unexpected signaling nodes and may provide mechanistic insights into some divergent phenotypes associated with Orai1 function.

Source: eLife

DOI: 10.7554/elife.25155

Authors: Yong Miao, Jaya Bhushan, Adish Dani, Monika Vig

Institutions: Washington University in St. Louis, Hope Center for Neurological Disorders

Language: English

Topic: Ion Channels and Receptors

Subfield: Sensory Systems

Field: Neuroscience

Domain: Life Sciences

SDG: Good health and well-being

Open Access status: gold

Estimated APC paid: $2,500