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 9.58
Times Cited 41
C.intestinalis / (O.japonicus) Wild C. int