CGC Bibliography Paper 5591

The mechanosensory protein MEC-6 is a subunit of the C. elegans touch-cell degenerin channel.

Chelur DS, Ernstrom GG, Goodman MB, Yao CA, Chen L, O'Hagan R, Chalfie M

Medline:

12478294

Citation:

Nature 420: 669-673 2002

Type:

ARTICLE

Genes:

mec-2 mec-4 mec-6 mec-10 mec-18

Abstract:

Mechanosensory transduction in touch receptor neurons is believed to be mediated by DEG/ENaC (degenerin/epithelial Na+ channel) proteins in nematodes and mammals(1). In the nematode Caenorhabditis elegans, gain-of-function mutations in the degenerin genes mec-4 and mec-10 (denoted mec-4(d) and mec-10(d), respectively) cause degeneration of the touch cells(2,3). This phenotype is completely suppressed by mutation in a third gene, mec-6 (refs 3, 4), that is needed for touch sensitivity. This last gene is also required for the function of other degenerins(4-8). Here we show that mec-6 encodes a single-pass membrane-spanning protein with limited similarity to paraoxonases, which are implicated in human coronary heart disease(9). This gene is expressed in muscle cells and in many neurons, including the six touch receptor neurons. MEC-6 increases amiloride-sensitive Na+ currents produced by MEC-4(d)/MEC-10(d) by similar to30-fold, and functions synergistically with MEC-2 (a stomatin-like protein(10) that regulates MEC-4(d)/MEC-10(d) channel activity(11)) to increase the currents by 200-fold. MEC-6 physically interacts with all three channel proteins. In vivo, MEC-6 colocalizes with MEC-4, and is required for punctate MEC-4 expression along touch-neuron processes. We propose that MEC-6 is a part of the degenerin channel complex that may