CALHM1/CALHM3 channel is intrinsically sorted to the basolateral membrane of epithelial cells including taste cells

Sci Rep. 2019 Feb 25;9(1):2681. doi: 10.1038/s41598-019-39593-5.

Abstract

The CALHM1/CALHM3 channel in the basolateral membrane of polarized taste cells mediates neurotransmitter release. However, mechanisms regulating its localization remain unexplored. Here, we identified CALHM1/CALHM3 in the basolateral membrane of type II taste cells in discrete puncta localized close to afferent nerve fibers. As in taste cells, CALHM1/CALHM3 was present in the basolateral membrane of model epithelia, although it was distributed throughout the membrane and did not show accumulation in puncta. We identified canonical basolateral sorting signals in CALHM1 and CALHM3: tyrosine-based and dileucine motifs. However, basolateral sorting remained intact in mutated channels lacking those signals, suggesting that non-canonical signals reside elsewhere. Our study demonstrates intrinsic basolateral sorting of CALHM channels in polarized cells, and provides mechanistic insights.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Calcium Channels / genetics
  • Calcium Channels / metabolism*
  • Cell Line, Tumor
  • Cell Membrane / metabolism*
  • Cell Polarity / genetics
  • Cells, Cultured
  • Dogs
  • Epithelial Cells / metabolism*
  • Humans
  • Ion Channel Gating / genetics
  • Madin Darby Canine Kidney Cells
  • Mice, Knockout
  • Protein Isoforms / genetics
  • Protein Isoforms / metabolism
  • Sequence Homology, Amino Acid
  • Synaptic Transmission / genetics
  • Taste Buds / cytology
  • Taste Buds / metabolism*

Substances

  • CALHM1 protein, mouse
  • Calcium Channels
  • Protein Isoforms