A5078994230- Calcium signaling and nucleotide metabolism
- Reproductive Biology and Fertility
- Sperm and Testicular Function
- Ion Channels and Receptors
- CRISPR and Genetic Engineering
- Adenosine and Purinergic Signaling
- Animal Genetics and Reproduction
- Ovarian function and disorders
- Ion channel regulation and function
- Pluripotent Stem Cells Research
- Pancreatic function and diabetes
- Autophagy in Disease and Therapy
- Cellular transport and secretion
- Piperaceae Chemical and Biological Studies
- Neuroethics, Human Enhancement, Biomedical Innovations
- Photoreceptor and optogenetics research
- Plant Molecular Biology Research
- Neuroscience, Education and Cognitive Function
- Reproductive biology and impacts on aquatic species
- Aquaculture Nutrition and Growth
- Biotechnology and Related Fields
- Virus-based gene therapy research
- Nicotinic Acetylcholine Receptors Study
- Cardiac electrophysiology and arrhythmias
- PARP inhibition in cancer therapy
University of Oxford
2016-2025
Mansfield University
2015
North Yorkshire County Council
2010
Universidad de Las Palmas de Gran Canaria
2010
University College London
1998-2002
Upon fertilisation by sperm, mammalian eggs are activated a series of intracellular Ca2+ oscillations that essential for embryo development. The mechanism which sperm induces this complex signalling phenomenon is unknown. One proposal the introduces an exclusive cytosolic factor into egg elicits serial release. ‘sperm factor’ hypothesis has not been ratified because sperm-specific protein generates repetitive transients and activation found. We identify novel, phospholipase C, PLCζ, triggers...
Egg activation, which is the first step in initiation of embryo development, involves both completion meiosis and progression into mitotic cycles. In mammals, fertilizing sperm delivers activating signal, consists oscillations free cytosolic Ca2+ concentration ([Ca2+]i). Intracytoplasmic injection (ICSI) a technique that vitro fertilization clinics use to treat myriad male factor infertility cases. Importantly, some patients who repeatedly fail ICSI also induce egg activation are, therefore,...
In mammals, oocyte activation at fertilization is thought to be induced by the sperm-specific phospholipase C zeta (PLCzeta). However, it still remains conclusively shown that PLCzeta endogenous agent of activation. Some types human infertility appear caused failure sperm activate and this may due specific defects in PLCzeta.Immunofluorescence studies showed localized equatorial region from fertile men, but deficient exhibited no signal same region. Immunoblot analysis revealed reduced...
SummaryIntracellular Ca2+ signals constitute key elements in signal transduction. Of the three major mobilizing messengers described, most potent, nicotinic acid adenine dinucleotide phosphate (NAADP) is least well understood terms of its molecular targets [1]. Recently, we showed that heterologous expression two-pore channel (TPC) proteins enhances NAADP-induced release, whereas NAADP response was abolished pancreatic beta cells from Tpcn2 gene knockout mice [2]. However, whether TPCs...
Nicotinic acid adenine dinucleotide phosphate (NAADP) is a molecule capable of initiating the release intracellular Ca<sup>2+</sup> required for many essential cellular processes. Recent evidence links two-pore channels (TPCs) with NAADP-induced from lysosome-like acidic organelles; however, there has been no direct demonstration that TPCs can act as NAADP-sensitive channels. Controversial also proposes ryanodine receptors primary target NAADP. We show TPC2, major lysosomal targeted isoform,...
Article14 April 2015Open Access Source Data Expression of Ca2+-permeable two-pore channels rescues NAADP signalling in TPC-deficient cells Margarida Ruas Department Pharmacology, University Oxford, UK Search for more papers by this author Lianne C Davis Cheng-Chang Chen Center Integrated Protein Science CIPS-M and Pharmacy – Drug Research, Ludwig-Maximilians-Universität München, Germany Anthony J Morgan Kai-Ting Chuang Timothy F Walseth Pharmacology Department, Minnesota, Minneapolis, MN,...
Significance The formation of new blood vessels (neoangiogenesis) accompanies tissue regeneration and healing, but is also crucial for tumor growth, hence understanding how capillaries are stimulated to grow in response local cues essential the much sought-after aim controlling this process. We have elucidated a Ca 2+ signaling pathway involving NAADP, TPCs, lysosomal release activated vascular endothelial cells by VEGF, main angiogenic growth factor, we show that can be abolished, cultured...
The endoplasmic reticulum (ER) and acidic organelles (endo-lysosomes) act as separate Ca2+ stores that release in response to the second messengers IP3 cADPR or NAADP (acidic organelles). Typically, trigger released from by subsequently recruits ryanodine receptors on ER, an anterograde signal important for amplification oscillations/waves. We therefore investigated whether ER can back organelles, using organelle pH a reporter of action. show activate pathway two ways: first, stimulating...
Activation of the egg by sperm is first, vital stage embryogenesis. The protein PLCζ has been proposed as physiological agent that triggers Ca2+ oscillations normally initiate Consistent with this, recombinant induces in eggs and debilitating mutations PLCZ1 gene are associated infertility men. However, there no evidence knockout encoding abolishes ability to induce eggs. Here, we show derived from Plcz1-/- male mice fail trigger eggs, cause polyspermy thus demonstrate these oscillations....
SummaryA cytotoxic T lymphocyte (CTL) kills an infected or tumorigenic cell by Ca2+-dependent exocytosis of cytolytic granules at the immunological synapse formed between two cells. Although inositol 1,4,5-trisphosphate (IP3)-mediated Ca2+ release from endoplasmic reticulum activates store-operated Ca2+-influx pathway that is necessary for exocytosis, it not a sufficient stimulus [1–4]. Here we identify Ca2+-mobilizing messenger nicotinic acid adenine dinucleotide phosphate (NAADP) and its...
Male factor and idiopathic infertility contribute significantly to global infertility, with abnormal testicular gene expression considered be a major cause. Certain types of male are caused by failure the sperm activate oocyte, process normally regulated calcium oscillations, thought induced sperm-specific phospholipase C, PLCzeta (PLCζ). Previously, we identified point mutation in an infertile resulting substitution histidine for proline at position 398 protein sequence (PLCζH398P), leading...
Nicotinic acid adenine dinucleotide phosphate (NAADP) is a messenger that regulates calcium release from intracellular acidic stores. Recent studies have identified two-pore channels (TPCs) as endolysosomal are regulated by NAADP; however, the nature of NAADP receptor binding site unknown. To further study sites, we synthesized and characterized [32P-5-azido]nicotinic ([32P-5N3]NAADP) photoaffinity probe. Photolysis sea urchin egg homogenates preincubated with [32P-5N3]NAADP resulted in...
Recent studies suggest that in mammals, oocyte activation at fertilization is triggered by a sperm-specific phospholipase C, PLCzeta. We investigated PLCzeta localization human spermatozoa.A polyclonal antibody was generated against and used immunoblotting immunofluorescence of ejaculated sperm uncapacitated capacitated states. An ionophore also to induce the acrosome reaction vitro.After verifying specificity anti-PLCzeta immunoblotting, showed predominant equatorial region, pattern...
Recently, we identified, for the first time, two-pore channels (TPCs, TPCN gene name) as a novel family of nicotinic acid adenine dinucleotide phosphate (NAADP)-gated, endolysosome-targeted calcium release channels. Significantly, three subtypes TPCs have been characterized, TPC1-3, with each being targeted to discrete acidic stores, namely lysosomes (TPC2) and endosomes (TPC1 TPC3). That act NAADP-gated is clear, given that NAADP binds high- low-affinity sites associated TPC2 thereby...
Ca(2+)-stimulated adenylyl cyclases (AC) are known to play important roles in neurons but have not previously been reported the heart. Here we present first evidence for selective expression of AC sino-atrial node (SAN) ventricular muscle guinea-pig The AC1 isoform was shown be SAN, both as mRNA using RT-PCR and protein immuno-blotting with a specific antibody. Confocal immuno-fluorescence studies detected membrane localization SAN cells, no muscle. AC8 may also SAN. functional importance...
Recent studies into the mechanisms of action Ca2+-mobilizing messenger NAADP (nicotinic acid–adenine dinucleotide phosphate) have demonstrated that a novel family intracellular Ca2+-release channels termed TPCs (two-pore channels) are components receptor. appear to be exclusively localized endolysosomal system. These findings confirm previous pharmacological and biochemical suggesting targets acidic Ca2+ stores rather than endoplasmic reticulum, major site other two principal messengers,...
Mammalian oocyte activation occurs via a series of intracellular calcium (Ca2+) oscillations thought to be induced by sperm-specific phospholipase C zeta (PLCζ). There is now strong evidence indicate that certain types human male infertility are caused failure the sperm activate in an appropriate manner. Molecular analysis PLCζ gene patient with deficiency has previously identified point mutation causing histidine proline substitution at residue 398 (PLCζH398P), leading abnormal Ca2+ release...
Organelle ion homeostasis within the endo-lysosomal system is critical for physiological functions. Two-pore channels (TPCs) are cation that reside in organelles, and overexpression results trafficking defects. However, impact of a lack TPC expression on unknown. Here, we characterize Tpcn1 two transgenic mouse lines (Tpcn1XG716 Tpcn1T159) show novel evolutionarily conserved Tpcn1B transcript from an alternative promoter, raising important questions regarding status mice recently described...