Hyperactivated motility is observed among sperm in the mammalian oviduct near the time of ovulation. It is characterized by high-amplitude, asymmetrical flagellar beating and assists sperm in penetrating the cumulus oophorus and zona pellucida. Elevated intracellular Ca2+ is required for the initiation of hyperactivated motility, suggesting that calmodulin (CALM) and Ca2+/CALM-stimulated pathways are involved. A demembranated sperm model was used to investigate the role of CALM in promoting hyperactivation. Ejaculated bovine sperm were demembranated and immobilized by brief exposure to Triton X-100. Motility was restored by addition of reactivation medium containing MgATP and Ca2+, and hyperactivation was observed as free Ca2+ was increased from 50 nM to 1 microM. However, when 2.5 mM Ca2+ was added to the demembranation medium to extract flagellar CALM, motility was not reactivated unless exogenous CALM was readded. The inclusion of anti-CALM IgG in the reactivation medium reduced the proportion hyperactivated in 1 microM Ca2+ to 5%. Neither control IgG, the CALM antagonist W-7, nor a peptide directed against the CALM-binding domain of myosin light chain kinase (MYLK2) inhibited hyperactivation. However, when sperm were reacti...Continue Reading
Electrophoretic transfer of proteins from polyacrylamide gels to nitrocellulose sheets: procedure and some applications
A computer-assisted assay for mouse sperm hyperactivation demonstrates that bicarbonate but not bovine serum albumin is required
Bending patterns of Chlamydomonas flagella: II. Calcium effects on reactivated Chlamydomonas flagella
Movement characteristics and acrosomal status of rabbit spermatozoa recovered at the site and time of fertilization
Immunocytochemical and biochemical evidence for the presence of calmodulin in bull sperm flagellum. Isolation and characterization of sperm calmodulin
Dephosphorylation of a 30-kDa protein of fowl spermatozoa by the addition of myosin light chain kinase substrate peptide inhibits the flagellar motility
Regulatory mechanisms of fowl sperm motility: possible role of endogenous myosin light chain kinase-like protein
Regulation of flagellar motility of fowl spermatozoa: evidence for the involvement of intracellular free Ca2+ and calmodulin
Intracellular calcium increases with hyperactivation in intact, moving hamster sperm and oscillates with the flagellar beat cycle
Regulation of human sperm motility and hyperactivation components by calcium, calmodulin, and protein phosphatases
Membrane hyperpolarization removes inactivation of Ca2+ channels, leading to Ca2+ influx and subsequent initiation of sperm motility in the common carp
Cyclic AMP- and calmodulin-dependent phosphorylation of 21 and 26 kda proteins in axoneme is a prerequisite for SAAF-induced motile activation in ascidian spermatozoa
Calmodulin signals capacitation and triggers the agonist-induced acrosome reaction in mouse spermatozoa
The motility of demembranated human spermatozoa is inhibited by free calcium ion activities of 500 nmol/L or more
An inositol 1,4,5-trisphosphate receptor-gated intracellular Ca(2+) store is involved in regulating sperm hyperactivated motility
Reactivation of motility of demembranated hamster spermatozoa: role of protein tyrosine kinase and protein phosphatases
Regulation of flagellar dynein by calcium and a role for an axonemal calmodulin and calmodulin-dependent kinase
Characterization of the intracellular calcium store at the base of the sperm flagellum that regulates hyperactivated motility
Flagellar radial spoke protein 2 is a calmodulin binding protein required for motility in Chlamydomonas reinhardtii.
Calmodulin/calmodulin-dependent protein kinase II mediates SAAF-induced motility activation of ascidian sperm
Effects of sodium fluoride on hyperactivation and Ca2+ signaling pathway in sperm from mice: an in vivo study
Familial frontotemporal dementia-associated presenilin-1 c.548G>T mutation causes decreased mRNA expression and reduced presenilin function in knock-in mice.
Androgen deprivation from pre-puberty to peripuberty interferes in proteins expression in pubertal and adult rat epididymis
Proteins associated with critical sperm functions and sperm head shape are differentially expressed in morphologically abnormal bovine sperm induced by scrotal insulation
Coupling biochemistry and hydrodynamics captures hyperactivated sperm motility in a simple flagellar model.
A cyclic adenosine 3',5'-monophosphate-dependent protein kinase C activation is involved in the hyperactivation of boar spermatozoa
Roles of extracellular Ca(2+) in the occurrence of full-type hyperactivation in boar ejaculated spermatozoa pre-incubated to induce the cAMP-triggered events
Identification of agrinSN isoform and muscle-specific receptor tyrosine kinase (MuSK) [corrected] in sperm
Non-genomic regulation and disruption of spermatozoal in vitro hyperactivation by oviductal hormones
Changes in calmodulin immunocytochemical localization associated with capacitation and acrosomal exocytosis of ram spermatozoa
Ca2+/Calmodulin-Dependent Protein Kinase Kinases (CaMKKs) Effects on AMP-Activated Protein Kinase (AMPK) Regulation of Chicken Sperm Functions
Mouse spermatozoa contain a nuclease that is activated by pretreatment with EGTA and subsequent calcium incubation
Study on the role of calmodulin in sperm function through the enrichment and identification of calmodulin-binding proteins in bovine ejaculated spermatozoa.
The flagellar protein Enkurin is required for mouse sperm motility and for transport through the female reproductive tract
The protein phosphatase with EF-hand domain 1 is a calmodulin-binding protein that interacts with proteins involved in sperm capacitation, binding to the zona pellucida, and motility.
Transwell isolation and difference analysis of capacitated boar sperm proteins based on the iTRAQ technique.
Calmodulin is involved in the occurrence of extracellular Ca2+ -dependent full-type hyperactivation in boar ejaculated spermatozoa incubated with cyclic AMP analogs.
EThcD and 213 nm UVPD for Top-Down Analysis of Bovine Seminal Plasma Proteoforms on Electrophoretic and Chromatographic Time Frames.
Mammalian sperm hyperactivation regulates navigation via physical boundaries and promotes pseudo-chemotaxis.
Calcium & Bioenergetics
Bioenergetic processes, including cellular respiration and photosynthesis, concern the transformation of energy by cells. Here is the latest research on the role of calcium in bioenergetics.
Bioinformatics in Biomedicine
Bioinformatics in biomedicine incorporates computer science, biology, chemistry, medicine, mathematics and statistics. Discover the latest research on bioinformatics in biomedicine here.