RRC ID 30195
Author Mizuno K, Shiba K, Okai M, Takahashi Y, Shitaka Y, Oiwa K, Tanokura M, Inaba K.
Title Calaxin drives sperm chemotaxis by Ca²⁺-mediated direct modulation of a dynein motor.
Journal Proc Natl Acad Sci U S A
Abstract Sperm chemotaxis occurs widely in animals and plants and plays an important role in the success of fertilization. Several studies have recently demonstrated that Ca(2+) influx through specific Ca(2+) channels is a prerequisite for sperm chemotactic movement. However, the regulator that modulates flagellar movement in response to Ca(2+) is unknown. Here we show that a neuronal calcium sensor, calaxin, directly acts on outer-arm dynein and regulates specific flagellar movement during sperm chemotaxis. Calaxin inhibition resulted in significant loss of sperm chemotactic movement, despite normal increases in intracellular calcium concentration. Using a demembranated sperm model, we demonstrate that calaxin is essential for generation and propagation of Ca(2+)-induced asymmetric flagellar bending. An in vitro motility assay revealed that calaxin directly suppressed the velocity of microtubule sliding by outer-arm dynein at high Ca(2+) concentrations. This study describes the missing link between chemoattractant-mediated Ca(2+) signaling and motor-driven microtubule sliding during sperm chemotaxis.
Volume 109(50)
Pages 20497-502
Published 2012-12-11
DOI 10.1073/pnas.1217018109
PII 1217018109
PMID 23169663
PMC PMC3528578
MeSH Animals Calcium Signaling / physiology Carbamates / pharmacology Chemotaxis / drug effects Chemotaxis / physiology Ciona intestinalis / cytology Ciona intestinalis / physiology Dyneins / physiology* Intracellular Calcium-Sensing Proteins / physiology* Male Microtubules / physiology Models, Biological Molecular Motor Proteins / physiology Piperidines / pharmacology Sperm Motility / physiology Sperm Tail / physiology Spermatozoa / drug effects Spermatozoa / physiology*
IF 9.412
Times Cited 41
C.intestinalis / (O.japonicus) Wild C. int