Recruitment of NAADP-sensitive acidic Ca2+ stores by glutamate

Vinita Pandey , Chia-Chen Chuang , Alexander M Lewis , Parvinder Aley , Eugen Brailoiu , Nae Dun , Grant C Churchill , Sandip Patel (1)

1 Department of Cell and Developmental Biology

NAADP is a novel second messenger thought to mobilize acidic Ca2+ stores that are functionally coupled to the endoplasmic reticulum. Although NAADP-sensitive Ca2+ stores have been described in neurons, the physiological cues that recruit them are not known. Here we show that in both hippocampal neurons and glia, extracellular application of glutamate in the absence of external Ca2+ evoked cytosolic Ca2+ signals that were inhibited by blockade of V-type ATPases or following osmotic bursting of lysosomes. The sensitivity of both cell types to glutamate correlated well with lysosomal Ca2+ content. However, interfering with acidic compartments was largely without effect on the Ca2+ content of the endoplasmic reticulum or Ca2+ signals in response to ATP. Glutamate but not ATP elevated cellular NAADP levels. Our data provide evidence for the agonist-specific recruitment of NAADP-sensitive Ca2+ stores by glutamate linking the actions of NAADP to a major neurotransmitter in the brain.

Mots clés: Life Sciences

Vinita Pandey, Chia-Chen Chuang, Alexander M Lewis, Parvinder Aley, Eugen Brailoiu, et al.. Recruitment of NAADP-sensitive acidic Ca2+ stores by glutamate. Biochemical Journal, 2009, 422 (3), pp.503-512. ⟨10.1042/BJ20090194⟩. ⟨hal-00479160⟩