Calcium-Activated Big-Conductance (BK) Potassium Channels Traffic through Nuclear Envelopes into Kinocilia in Ray Electrosensory Cells
Year: 2023
Type: article
Abstract: Electroreception through ampullae of Lorenzini in the little skate, Leucoraja erinacea , involves functional coupling between voltage-activated calcium channels (CaV1.3, cacna1d ) and calcium-activated big conductance potassium (BK) channels (BK, kcnma1 ). Whole mount confocal microscopy was used to characterize expression of BK and CaV1.3 in intact ampullae. BK and CaV1.3 are present in electrosensory cell plasma membranes and colocalize with lamin B1 in nuclear envelopes and kinocilia. Predicted nuclear localization signals (NLS) were identified in BK and CaV1.3 by bioinformatic sequence analyses. The BK NLS is bipartite, occurs at an alternative splice site for the mammalian STREX exon and is modified by post-translational phosphorylation. Nuclear localization of skate BK channels was characterized in heterologously-transfected HEK293 cells. Double point mutations in the bipartite NLS (KR to AA, or SVLS to AVLA) independently attenuated BK channel nuclear localization, illustrating that BK trafficking into nuclei and electrosensory cell kinocilia is regulated through a newly identified bipartite NLS.
Source: Cells
Institutions: Stanford Medicine, Stanford University
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: gold
Estimated APC paid: $2,669
OpenAlex ID: W4386069862