RRC ID 46526
Author Wagner J, Allman E, Taylor A, Ulmschneider K, Kovanda T, Ulmschneider B, Nehrke K, Peters MA.
Title A calcineurin homologous protein is required for sodium-proton exchange events in the C. elegans intestine.
Journal Am J Physiol Cell Physiol
Abstract Caenorhabditis elegans defecation is a rhythmic behavior, composed of three sequential muscle contractions, with a 50-s periodicity. The motor program is driven by oscillatory calcium signaling in the intestine. Proton fluxes, which require sodium-proton exchangers at the apical and basolateral intestinal membranes, parallel the intestinal calcium flux. These proton shifts are critical for defecation-associated muscle contraction, nutrient uptake, and longevity. How sodium-proton exchangers are activated in time with intestinal calcium oscillation is not known. The posterior body defecation contraction mutant (pbo-1) encodes a calcium-binding protein with homology to calcineurin homologous proteins, which are putative cofactors for mammalian sodium-proton exchangers. Loss of pbo-1 function results in a weakened defecation muscle contraction and a caloric restriction phenotype. Both of these phenotypes also arise from dysfunctions in pH regulation due to mutations in intestinal sodium-proton exchangers. Dynamic, in vivo imaging of intestinal proton flux in pbo-1 mutants using genetically encoded pH biosensors demonstrates that proton movements associated with these sodium-proton exchangers are significantly reduced. The basolateral acidification that signals the first defecation motor contraction is scant in the mutant compared with a normal animal. Luminal and cytoplasmic pH shifts are much reduced in the absence of PBO-1 compared with control animals. We conclude that pbo-1 is required for normal sodium-proton exchanger activity and may couple calcium and proton signaling events.
Volume 301(6)
Pages C1389-403
Published 2011-12-1
DOI 10.1152/ajpcell.00139.2011
PII ajpcell.00139.2011
PMID 21865588
PMC PMC3273995
MeSH Animals Animals, Genetically Modified Caenorhabditis elegans / genetics Caenorhabditis elegans / metabolism* Caenorhabditis elegans Proteins / genetics Caenorhabditis elegans Proteins / metabolism* Calcineurin / genetics Calcineurin / metabolism* Calcium / metabolism Defecation / physiology* Intestines / physiology* Muscle Contraction / physiology* Oligonucleotide Array Sequence Analysis Polymerase Chain Reaction Sodium-Hydrogen Exchangers / genetics Sodium-Hydrogen Exchangers / metabolism*
IF 3.485
Times Cited 11
C.elegans tm3716