Calcineurin regulates enteric muscle contraction through EXP-1, excitatory GABA-gated channel, in C. elegans.
The enteric muscle contraction (EMC) is the last step of the defecation behavior which occurs every 50 s in Caenorhabditis elegans. This EMC is regulated by intestinal and anal depressor muscles, which are innervated by GABA motor neurons. Our data show that calcineurin (tax-6) is expressed in intestinal muscle and anal depressor muscle, and the gain-of-function mutant of calcineurin, tax-6(jh107), shows defects in enteric muscle contractions. In addition, the intracellular region of EXP-1, an excitatory GABA receptor, specifically binds to calcineurin A. This interaction between TAX-6 and EXP-1 appears to be independent of both calcium and CNB, which is the calcium-binding regulatory subunit. Genetic evidence of epistasis between cnb-1(jh103) and exp-1(sa6) suggests that calcineurin functions as a negative regulator of excitatory GABA receptor in GABA signaling in C.elegans.
Lee
Jungsoo
J
Department of Life Science, Gwangju Institute of Science and Technology, Gwangju 500-712, Korea.
Song
Hyun-Ok
HO
Jee
Changhoon
C
Vanoaica
Liviu
L
Ahnn
Joohong
J
D000595:Amino Acid Sequence; D000818:Animals; D017173:Caenorhabditis elegans / Q000235:genetics / Q000502:physiology*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000502:physiology*; D019703:Calcineurin / Q000502:physiology*; D004064:Digestive System / Q000294:innervation; D004068:Digestive System Physiological Phenomena; D008969:Molecular Sequence Data; D009046:Motor Neurons / Q000502:physiology; D009119:Muscle Contraction / Q000502:physiology; D009130:Muscle, Smooth / Q000294:innervation / Q000502:physiology; D009154:Mutation; D018079:Receptors, GABA / Q000235:genetics / Q000502:physiology*; D015398:Signal Transduction
D029742:Caenorhabditis elegans Proteins; C504796:EXP-1 protein, C elegans; D018079:Receptors, GABA; D019703:Calcineurin