[The effect of Ca2+ on the properties of the large conductance cation channels of the nuclear envelope of the cerebellar neurons].

Abstract

Previously we have found the large conductance cation channels (LCCC) in the nuclear membranes, where inositol-1,4,5-triphosphate receptors (IP3Rs) were also observed. Probably IP3Rs and LCCC are functionally connected: LCCC may provide the counterflow of K+, which prevent the formation of the negative potential in the lumen of the nuclear envelope and in such way may prolong the Ca2+ releasing by IP3Rs. LCCC are poorly studied and their molecular nature is still unknown. We investigated the effect of Ca2+ on properties of these channels. Our results demonstrated the main biophysical properties of LCCC changed significantly neither in Ca(2+)-free solution, nor with high concentrations of Ca2+ in the nuclear lumen. So, the level of Ca2+ repletion of the store does not influence the activity of LCCC.