1
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Arige V, Wagner LE, Malik S, Baker MR, Fan G, Serysheva II, Yule DI. Functional investigation of a putative calcium-binding site involved in the inhibition of inositol 1,4,5-trisphosphate receptor activity. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.08.16.608318. [PMID: 39211071 PMCID: PMC11360954 DOI: 10.1101/2024.08.16.608318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/04/2024]
Abstract
A wide variety of factors influence inositol 1,4,5-trisphosphate (IP 3 ) receptor (IP 3 R) activity resulting in modulation of intracellular Ca 2+ release. This regulation is thought to define the spatio-temporal patterns of Ca 2+ signals necessary for the appropriate activation of downstream effectors. The binding of both IP 3 and Ca 2+ are obligatory for IP 3 R channel opening, however, Ca 2+ regulates IP 3 R activity in a biphasic manner. Mutational studies have revealed that Ca 2+ binding to a high-affinity pocket formed by the ARM3 domain and linker domain promotes IP 3 R channel opening without altering the Ca 2+ dependency for channel inactivation. These data suggest a distinct low-affinity Ca 2+ binding site is responsible for the reduction in IP 3 R activity at higher [Ca 2+ ]. We determined the consequences of mutating a cluster of acidic residues in the ARM2 and central linker domain reported to coordinate Ca 2+ in cryo-EM structures of the IP 3 R type 3. This site is termed the "CD Ca 2+ binding site" and is well-conserved in all IP 3 R sub-types. We show that the CD site Ca 2+ binding mutants where the negatively charged glutamic acid residues are mutated to alanine exhibited enhanced sensitivity to IP 3 -generating agonists. Ca 2+ binding mutants displayed spontaneous elemental Ca 2+ events (Ca 2+ puffs) and the number of IP 3 -induced Ca 2+ puffs was significantly augmented in cells stably expressing Ca 2+ binding site mutants. When measured with "on-nucleus" patch clamp, the inhibitory effect of high [Ca 2+ ] on single channel-open probability (P o ) was reduced in mutant channels and this effect was dependent on [ATP]. These results indicate that Ca 2+ binding to the putative CD Ca 2+ inhibitory site facilitates the reduction in IP 3 R channel activation when cytosolic [ATP] is reduced and suggest that at higher [ATP], additional Ca 2+ binding motifs may contribute to the biphasic regulation of IP 3 -induced Ca 2+ release.
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2
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Harris S, Putra M, Gilmore KL, Vora NL. Two unrelated fetuses with ITPR1 missense variants and fetal hydrops. Prenat Diagn 2023; 43:1463-1466. [PMID: 37705153 PMCID: PMC10686210 DOI: 10.1002/pd.6439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 08/25/2023] [Accepted: 08/30/2023] [Indexed: 09/15/2023]
Abstract
We describe two fetuses from unrelated families with likely pathogenic variants in ITPR1 that presented with nonimmune fetal hydrops. Trio exome sequencing revealed a de novo heterozygous likely pathogenic missense variant c.7636G > A (p.Val2531Met) in ITPR1 (NM_001378452.1) in proband 1 and a de novo heterozygous likely pathogenic missense variant c.34G > A [p.Gly12Arg] in proband 2. Variants in ITPR1 have been associated with several genetic conditions, including spinocerebellar ataxia 15, spinocerebellar ataxia 29, and Gillespie syndrome. Our report on two patients details a previously undescribed severe fetal presentation of nonimmune hydrops fetalis associated with missense variants in the ITPR1 gene.
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Affiliation(s)
- Sarah Harris
- Division of Maternal Fetal Medicine, Department of Obstetrics and Gynecology, Atrium Health Wake Forest Baptist, Wake Forest University School of Medicine, Winston-Salem, North Carolina, USA
| | - Manesha Putra
- Division of Maternal Fetal Medicine, Department of Obstetrics and Gynecology, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Kelly L Gilmore
- Division of Maternal Fetal Medicine, Department of Obstetrics and Gynecology, University of North Carolina School of Medicine, Chapel Hill, North Carolina, USA
| | - Neeta L Vora
- Division of Maternal Fetal Medicine, Department of Obstetrics and Gynecology, University of North Carolina School of Medicine, Chapel Hill, North Carolina, USA
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3
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Takano T, Yule DI. Ca 2+ signals in pancreatic acinar cells in response to physiological stimulation in vivo. J Physiol 2023. [PMID: 36965132 DOI: 10.1113/jp284469] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Accepted: 03/08/2023] [Indexed: 03/27/2023] Open
Abstract
The exocrine pancreas secretes fluid and digestive enzymes in response to parasympathetic release of acetylcholine (ACh) via the vagus nerve and the gut hormone cholecystokinin (CCK). Both secretion of fluid and exocytosis of secretory granules containing enzymes and zymogens are dependent on an increase in the cytosolic [Ca2+ ] in acinar cells. It is thought that the specific spatiotemporal characteristics of the Ca2+ signals are fundamental for appropriate secretion and that these properties are disrupted in disease states in the pancreas. While extensive research has been performed to characterize Ca2+ signalling in acinar cells, this has exclusively been achieved in ex vivo preparations of exocrine cells, where it is difficult to mimic physiological conditions. Here we have developed a method to optically observe pancreatic acinar Ca2+ signals in vivo using a genetically expressed Ca2+ indicator and imaged with multi-photon microscopy in live animals. In vivo, acinar cells exhibited baseline activity in fasted animals, which was dependent on CCK1 receptors (CCK1Rs). Both stimulation of intrinsic nervous input and administration of systemic CCK induced oscillatory activity in a proportion of the cells, but the maximum frequencies were vastly different. Upon feeding, oscillatory activity was also observed, which was dependent on CCK1Rs. No evidence of a vago-vagal reflex mediating the effects of CCK was observed. Our in vivo method revealed the spatial and temporal profile of physiologically evoked Ca2+ signals, which will provide new insights into future studies of the mechanisms underlying exocrine physiology and that are disrupted in pathological conditions. KEY POINTS: In the exocrine pancreas, the spatiotemporal properties of Ca2+ signals are fundamentally important for the appropriate stimulation of secretion by the neurotransmitter acetylcholine and gut hormone cholecystokinin. These characteristics were previously defined in ex vivo studies. Here we report the spatiotemporal characteristics of Ca2+ signals in vivo in response to physiological stimulation in a mouse engineered to express a Ca2+ indicator in acinar cells. Specific Ca2+ 'signatures' probably important for stimulating secretion are evoked in vivo in fasted animals, by feeding, neural stimulation and cholecystokinin administration. The Ca2+ signals are probably the result of the direct action of ACh and CCK on acinar cells and not indirectly through a vago-vagal reflex.
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Affiliation(s)
- Takahiro Takano
- Department of Pharmacology and Physiology, University of Rochester, Rochester, New York, USA
| | - David I Yule
- Department of Pharmacology and Physiology, University of Rochester, Rochester, New York, USA
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4
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Tambeaux A, Aguilar-Sánchez Y, Santiago DJ, Mascitti M, DiNovo KM, Mejía-Alvarez R, Fill M, Wayne Chen SR, Ramos-Franco J. Ligand sensitivity of type-1 inositol 1,4,5-trisphosphate receptor is enhanced by the D2594K mutation. Pflugers Arch 2023; 475:569-581. [PMID: 36881190 PMCID: PMC10105685 DOI: 10.1007/s00424-023-02796-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 02/06/2023] [Accepted: 02/12/2023] [Indexed: 03/08/2023]
Abstract
Inositol 1,4,5-trisphosphate receptor (IP3R) and ryanodine receptor (RyR) are homologous cation channels that mediate release of Ca2+ from the endoplasmic/sarcoplasmic reticulum (ER/SR) and thereby are involved in many physiological processes. In previous studies, we determined that when the D2594 residue, located at or near the gate of the IP3R type 1, was replaced by lysine (D2594K), a gain of function was obtained. This mutant phenotype was characterized by increased IP3 sensitivity. We hypothesized the IP3R1-D2594 determines the ligand sensitivity of the channel by electrostatically affecting the stability of the closed and open states. To test this possibility, the relationship between the D2594 site and IP3R1 regulation by IP3, cytosolic, and luminal Ca2+ was determined at the cellular, subcellular, and single-channel levels using fluorescence Ca2+ imaging and single-channel reconstitution. We found that in cells, D2594K mutation enhances the IP3 ligand sensitivity. Single-channel IP3R1 studies revealed that the conductance of IP3R1-WT and -D2594K channels is similar. However, IP3R1-D2594K channels exhibit higher IP3 sensitivity, with substantially greater efficacy. In addition, like its wild type (WT) counterpart, IP3R1-D2594K showed a bell-shape cytosolic Ca2+-dependency, but D2594K had greater activity at each tested cytosolic free Ca2+ concentration. The IP3R1-D2594K also had altered luminal Ca2+ sensitivity. Unlike IP3R1-WT, D2594K channel activity did not decrease at low luminal Ca2+ levels. Taken together, our functional studies indicate that the substitution of a negatively charged residue by a positive one at the channels' pore cytosolic exit affects the channel's gating behavior thereby explaining the enhanced ligand-channel's sensitivity.
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Affiliation(s)
- Allison Tambeaux
- Department of Physiology and Biophysics, Rush University Medical Center, Chicago, IL, USA
| | - Yuriana Aguilar-Sánchez
- Department of Physiology and Biophysics, Rush University Medical Center, Chicago, IL, USA.,Molecular Physiology & Biophysics, Baylor College of Medicine, Houston, TX, USA
| | - Demetrio J Santiago
- Department of Physiology and Biophysics, Rush University Medical Center, Chicago, IL, USA.,Centro Nacional de Investigaciones Cardiovasculares, Madrid, Spain
| | | | - Karyn M DiNovo
- Department of Physiology, Midwestern University, Downers Grove, IL, USA
| | | | - Michael Fill
- Department of Physiology and Biophysics, Rush University Medical Center, Chicago, IL, USA
| | - S R Wayne Chen
- Department of Physiology and Biophysics, Rush University Medical Center, Chicago, IL, USA.,Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, Calgary, AB, Canada
| | - Josefina Ramos-Franco
- Department of Physiology and Biophysics, Rush University Medical Center, Chicago, IL, USA.
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5
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Terry LE, Arige V, Neumann J, Wahl AM, Knebel TR, Chaffer JW, Malik S, Liston A, Humblet-Baron S, Bultynck G, Yule DI. Missense mutations in inositol 1,4,5-trisphosphate receptor type 3 result in leaky Ca 2+ channels and activation of store-operated Ca 2+ entry. iScience 2022; 25:105523. [PMID: 36444295 PMCID: PMC9700043 DOI: 10.1016/j.isci.2022.105523] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 10/10/2022] [Accepted: 11/04/2022] [Indexed: 11/09/2022] Open
Abstract
Mutations in all subtypes of the inositol 1,4,5-trisphosphate receptor Ca2+ release channel are associated with human diseases. In this report, we investigated the functionality of three neuropathy-associated missense mutations in IP3R3 (V615M, T1424M, and R2524C). The mutants only exhibited function when highly over-expressed compared to endogenous hIP3R3. All variants resulted in elevated basal cytosolic Ca2+ levels, decreased endoplasmic reticulum Ca2+ store content, and constitutive store-operated Ca2+ entry in the absence of any stimuli, consistent with a leaky IP3R channel pore. These variants differed in channel function; when stably over-expressed the R2524C mutant was essentially dead, V615M was poorly functional, and T1424M exhibited activity greater than that of the corresponding wild-type following threshold stimulation. These results demonstrate that a common feature of these mutations is decreased IP3R3 function. In addition, these mutations exhibit a novel phenotype manifested as a constitutively open channel, which inappropriately gates SOCE in the absence of stimulation.
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Affiliation(s)
- Lara E. Terry
- Department of Pharmacology and Physiology, University of Rochester, Rochester, NY 14642, USA
| | - Vikas Arige
- Department of Pharmacology and Physiology, University of Rochester, Rochester, NY 14642, USA
| | - Julika Neumann
- KU Leuven, Department of Microbiology and Immunology, Leuven, Belgium
| | - Amanda M. Wahl
- Department of Pharmacology and Physiology, University of Rochester, Rochester, NY 14642, USA
| | - Taylor R. Knebel
- Department of Pharmacology and Physiology, University of Rochester, Rochester, NY 14642, USA
| | - James W. Chaffer
- Department of Pharmacology and Physiology, University of Rochester, Rochester, NY 14642, USA
| | - Sundeep Malik
- Department of Pharmacology and Physiology, University of Rochester, Rochester, NY 14642, USA
| | - Adrian Liston
- KU Leuven, Department of Microbiology and Immunology, Leuven, Belgium
| | | | - Geert Bultynck
- KU Leuven, Laboratory of Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine, Leuven, Belgium
| | - David I. Yule
- Department of Pharmacology and Physiology, University of Rochester, Rochester, NY 14642, USA
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6
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Means RE, Katz SG. Balancing life and death: BCL-2 family members at diverse ER-mitochondrial contact sites. FEBS J 2022; 289:7075-7112. [PMID: 34668625 DOI: 10.1111/febs.16241] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 10/11/2021] [Accepted: 10/19/2021] [Indexed: 01/13/2023]
Abstract
The outer mitochondrial membrane is a busy place. One essential activity for cellular survival is the regulation of membrane integrity by the BCL-2 family of proteins. Another critical facet of the outer mitochondrial membrane is its close approximation with the endoplasmic reticulum. These mitochondrial-associated membranes (MAMs) occupy a significant fraction of the mitochondrial surface and serve as key signaling hubs for multiple cellular processes. Each of these pathways may be considered as forming their own specialized MAM subtype. Interestingly, like membrane permeabilization, most of these pathways play critical roles in regulating cellular survival and death. Recently, the pro-apoptotic BCL-2 family member BOK has been found within MAMs where it plays important roles in their structure and function. This has led to a greater appreciation that multiple BCL-2 family proteins, which are known to participate in numerous functions throughout the cell, also have roles within MAMs. In this review, we evaluate several MAM subsets, their role in cellular homeostasis, and the contribution of BCL-2 family members to their functions.
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Affiliation(s)
- Robert E Means
- Department of Pathology, Yale University School of Medicine, New Haven, CT, USA
| | - Samuel G Katz
- Department of Pathology, Yale University School of Medicine, New Haven, CT, USA
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7
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Arige V, Yule DI. Spatial and temporal crosstalk between the cAMP and Ca 2+ signaling systems. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2022; 1869:119293. [PMID: 35588944 DOI: 10.1016/j.bbamcr.2022.119293] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 05/09/2022] [Accepted: 05/11/2022] [Indexed: 12/31/2022]
Abstract
The ubiquitous secondary messengers, Ca2+ and cAMP, play a vital role in shaping a diverse array of physiological processes. More significantly, accumulating evidence over the past several decades underpin extensive crosstalk between these two canonical messengers in discrete sub-cellular nanodomains across various cell types. Within such specialized nanodomains, each messenger fine-tunes signaling to maintain homeostasis by manipulating the activities of cellular machinery accountable for the metabolism or activity of the complementary pathway. Interaction between these messengers is ensured by scaffolding proteins which tether components of the signaling machinery in close proximity. Disruption of dynamic communications between Ca2+ and cAMP at these loci consequently is linked to several pathological conditions. This review summarizes recent novel mechanisms underlying effective crosstalk between Ca2+ and cAMP in such nanodomains.
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Affiliation(s)
- Vikas Arige
- Department of Pharmacology and Physiology, University of Rochester, 601 Elmwood Avenue, Rochester, NY 14642, USA
| | - David I Yule
- Department of Pharmacology and Physiology, University of Rochester, 601 Elmwood Avenue, Rochester, NY 14642, USA..
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8
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Ahmad M, Ong HL, Saadi H, Son GY, Shokatian Z, Terry LE, Trebak M, Yule DI, Ambudkar I. Functional communication between IP 3R and STIM2 at subthreshold stimuli is a critical checkpoint for initiation of SOCE. Proc Natl Acad Sci U S A 2022; 119:e2114928118. [PMID: 35022238 PMCID: PMC8784118 DOI: 10.1073/pnas.2114928118] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Accepted: 11/19/2021] [Indexed: 02/08/2023] Open
Abstract
Stromal interaction molecules, STIM1 and STIM2, sense decreases in the endoplasmic reticulum (ER) [Ca2+] ([Ca2+]ER) and cluster in ER-plasma membrane (ER-PM) junctions where they recruit and activate Orai1. While STIM1 responds when [Ca2+]ER is relatively low, STIM2 displays constitutive clustering in the junctions and is suggested to regulate basal Ca2+ entry. The cellular cues that determine STIM2 clustering under basal conditions is not known. By using gene editing to fluorescently tag endogenous STIM2, we report that endogenous STIM2 is constitutively localized in mobile and immobile clusters. The latter associate with ER-PM junctions and recruit Orai1 under basal conditions. Agonist stimulation increases immobile STIM2 clusters, which coordinate recruitment of Orai1 and STIM1 to the junctions. Extended synaptotagmin (E-Syt)2/3 are required for forming the ER-PM junctions, but are not sufficient for STIM2 clustering. Importantly, inositol 1,4,5-triphosphate receptor (IP3R) function and local [Ca2+]ER are the main drivers of immobile STIM2 clusters. Enhancing, or decreasing, IP3R function at ambient [IP3] causes corresponding increase, or attenuation, of immobile STIM2 clusters. We show that immobile STIM2 clusters denote decreases in local [Ca2+]ER mediated by IP3R that is sensed by the STIM2 N terminus. Finally, under basal conditions, ambient PIP2-PLC activity of the cell determines IP3R function, immobilization of STIM2, and basal Ca2+ entry while agonist stimulation augments these processes. Together, our findings reveal that immobilization of STIM2 clusters within ER-PM junctions, a first response to ER-Ca2+ store depletion, is facilitated by the juxtaposition of IP3R and marks a checkpoint for initiation of Ca2+ entry.
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Affiliation(s)
- Moaz Ahmad
- Secretory Physiology Section, National Institute of Dental and Craniofacial Research, NIH, Bethesda, MD 20892
| | - Hwei Ling Ong
- Secretory Physiology Section, National Institute of Dental and Craniofacial Research, NIH, Bethesda, MD 20892
| | - Hassan Saadi
- Secretory Physiology Section, National Institute of Dental and Craniofacial Research, NIH, Bethesda, MD 20892
| | - Ga-Yeon Son
- Secretory Physiology Section, National Institute of Dental and Craniofacial Research, NIH, Bethesda, MD 20892
| | - Zahra Shokatian
- Secretory Physiology Section, National Institute of Dental and Craniofacial Research, NIH, Bethesda, MD 20892
| | - Lara E Terry
- Department of Pharmacology and Physiology, University of Rochester, Rochester, NY 14526
| | - Mohamed Trebak
- Department of Pharmacology and Chemical Biology, Vascular Medicine Institute, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261
| | - David I Yule
- Department of Pharmacology and Physiology, University of Rochester, Rochester, NY 14526
| | - Indu Ambudkar
- Secretory Physiology Section, National Institute of Dental and Craniofacial Research, NIH, Bethesda, MD 20892;
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9
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Arige V, Terry LE, Malik S, Knebel TR, Wagner II LE, Yule DI. CREB regulates the expression of type 1 inositol 1,4,5-trisphosphate receptors. J Cell Sci 2021; 134:jcs258875. [PMID: 34533188 PMCID: PMC8601716 DOI: 10.1242/jcs.258875] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 09/13/2021] [Indexed: 12/16/2022] Open
Abstract
Inositol 1,4,5-trisphosphate (IP3) receptors (IP3Rs) play a central role in regulating intracellular Ca2+ signals in response to a variety of internal and external cues. Dysregulation of IP3R signaling is the underlying cause for numerous pathological conditions. It is well established that the activities of IP3Rs are governed by several post-translational modifications, including phosphorylation by protein kinase A (PKA). However, the long-term effects of PKA activation on expression of IP3R subtypes remains largely unexplored. In this report, we investigate the effects of chronic stimulation and tonic activity of PKA on the expression of IP3R subtypes. We demonstrate that expression of the type 1 IP3R (IP3R1) is augmented upon prolonged activation of PKA or upon ectopic overexpression of cyclic AMP-response element-binding protein (CREB) without altering IP3R2 and IP3R3 abundance. By contrast, inhibition of PKA or blocking CREB diminished IP3R1 expression. We also demonstrate that agonist-induced Ca2+-release mediated by IP3R1 is significantly attenuated upon blocking of CREB. Moreover, CREB - by regulating the expression of KRAS-induced actin-interacting protein (KRAP) - ensures correct localization and licensing of IP3R1. Overall, we report a crucial role for CREB in governing both the expression and correct localization of IP3R1. This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
| | | | | | | | | | - David I. Yule
- Department of Pharmacology and Physiology, University of Rochester, Rochester, NY 14642, USA
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10
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Keehan L, Jiang MM, Li X, Marom R, Dai H, Murdock D, Liu P, Hunter JV, Heaney JD, Robak L, Emrick L, Lotze T, Blieden LS, Lewis RA, Levin AV, Capasso J, Craigen WJ, Rosenfeld JA, Lee B, Burrage LC. A novel de novo intronic variant in ITPR1 causes Gillespie syndrome. Am J Med Genet A 2021; 185:2315-2324. [PMID: 33949769 DOI: 10.1002/ajmg.a.62232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Accepted: 04/01/2021] [Indexed: 11/07/2022]
Abstract
Gillespie syndrome (GLSP) is characterized by bilateral symmetric partial aplasia of the iris presenting as a fixed and large pupil, cerebellar hypoplasia with ataxia, congenital hypotonia, and varying levels of intellectual disability. GLSP is caused by either biallelic or heterozygous, dominant-negative, pathogenic variants in ITPR1. Here, we present a 5-year-old male with GLSP who was found to have a heterozygous, de novo intronic variant in ITPR1 (NM_001168272.1:c.5935-17G > A) through genome sequencing (GS). Sanger sequencing of cDNA from this individual's fibroblasts showed the retention of 15 nucleotides from intron 45, which is predicted to cause an in-frame insertion of five amino acids near the C-terminal transmembrane domain of ITPR1. In addition, qPCR and cDNA sequencing demonstrated reduced expression of both ITPR1 alleles in fibroblasts when compared to parental samples. Given the close proximity of the predicted in-frame amino acid insertion to the site of previously described heterozygous, de novo, dominant-negative, pathogenic variants in GLSP, we predict that this variant also has a dominant-negative effect on ITPR1 channel function. Overall, this is the first report of a de novo intronic variant causing GLSP, which emphasizes the utility of GS and cDNA studies for diagnosing patients with a clinical presentation of GLSP and negative clinical exome sequencing.
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Affiliation(s)
- Laura Keehan
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA
| | - Ming-Ming Jiang
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA
| | - Xiaohui Li
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA
| | - Ronit Marom
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA.,Texas Children's Hospital, Houston, Texas, USA
| | - Hongzheng Dai
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA.,Baylor Genetics, Houston, Texas, USA
| | - David Murdock
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA
| | - Pengfei Liu
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA.,Baylor Genetics, Houston, Texas, USA
| | - Jill V Hunter
- Texas Children's Hospital, Houston, Texas, USA.,Department of Radiology, Baylor College of Medicine, Houston, Texas, USA
| | - Jason D Heaney
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA
| | - Laurie Robak
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA.,Texas Children's Hospital, Houston, Texas, USA
| | - Lisa Emrick
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA.,Texas Children's Hospital, Houston, Texas, USA.,Department of Pediatrics, Baylor College of Medicine (BCM), Houston, Texas, USA.,Division of Neurology and Developmental Neuroscience, Department of Pediatrics, BCM, Houston, Texas, USA
| | - Timothy Lotze
- Texas Children's Hospital, Houston, Texas, USA.,Department of Pediatrics, Baylor College of Medicine (BCM), Houston, Texas, USA.,Division of Neurology and Developmental Neuroscience, Department of Pediatrics, BCM, Houston, Texas, USA
| | - Lauren S Blieden
- Cullen Eye Institute, Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, USA
| | | | - Richard Alan Lewis
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA.,Texas Children's Hospital, Houston, Texas, USA.,Cullen Eye Institute, Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, USA
| | - Alex V Levin
- Flaum Eye Institute and Golisano Children's Hospital, Departments of Ophthalmology and Pediatrics, University of Rochester, Rochester, New York, USA
| | - Jenina Capasso
- Flaum Eye Institute and Golisano Children's Hospital, Departments of Ophthalmology and Pediatrics, University of Rochester, Rochester, New York, USA
| | - William J Craigen
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA.,Texas Children's Hospital, Houston, Texas, USA
| | - Jill A Rosenfeld
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA
| | - Brendan Lee
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA.,Texas Children's Hospital, Houston, Texas, USA
| | - Lindsay C Burrage
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA.,Texas Children's Hospital, Houston, Texas, USA
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11
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Terry LE, Alzayady KJ, Wahl AM, Malik S, Yule DI. Disease-associated mutations in inositol 1,4,5-trisphosphate receptor subunits impair channel function. J Biol Chem 2020; 295:18160-18178. [PMID: 33093175 PMCID: PMC7939385 DOI: 10.1074/jbc.ra120.015683] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 10/21/2020] [Indexed: 01/27/2023] Open
Abstract
The inositol 1,4,5-trisphosphate (IP3) receptors (IP3Rs), which form tetrameric channels, play pivotal roles in regulating the spatiotemporal patterns of intracellular calcium signals. Mutations in IP3Rs have been increasingly associated with many debilitating human diseases such as ataxia, Gillespie syndrome, and generalized anhidrosis. However, how these mutations affect IP3R function, and how the perturbation of as-sociated calcium signals contribute to the pathogenesis and severity of these diseases remains largely uncharacterized. Moreover, many of these diseases occur as the result of autosomal dominant inheritance, suggesting that WT and mutant subunits associate in heterotetrameric channels. How the in-corporation of different numbers of mutant subunits within the tetrameric channels affects its activities and results in different disease phenotypes is also unclear. In this report, we investigated representative disease-associated missense mutations to determine their effects on IP3R channel activity. Additionally, we designed concatenated IP3R constructs to create tetrameric channels with a predefined subunit composition to explore the functionality of heteromeric channels. Using calcium imaging techniques to assess IP3R channel function, we observed that all the mutations studied resulted in severely attenuated Ca2+ release when expressed as homotetramers. However, some heterotetramers retained varied degrees of function dependent on the composition of the tetramer. Our findings suggest that the effect of mutations depends on the location of the mutation in the IP3R structure, as well as on the stoichiometry of mutant subunits assembled within the tetrameric channel. These studies provide insight into the pathogenesis and penetrance of these devastating human diseases.
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Affiliation(s)
- Lara E Terry
- Department of Pharmacology and Physiology, University of Rochester, Rochester, New York, USA
| | - Kamil J Alzayady
- Department of Pharmacology and Physiology, University of Rochester, Rochester, New York, USA
| | - Amanda M Wahl
- Department of Pharmacology and Physiology, University of Rochester, Rochester, New York, USA
| | - Sundeep Malik
- Department of Pharmacology and Physiology, University of Rochester, Rochester, New York, USA
| | - David I Yule
- Department of Pharmacology and Physiology, University of Rochester, Rochester, New York, USA.
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12
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Lemos FO, Guerra MT, Leite MDF. Inositol 1,4,5 trisphosphate receptors in secretory epithelial cells of the gastrointestinal tract. CURRENT OPINION IN PHYSIOLOGY 2020. [DOI: 10.1016/j.cophys.2020.08.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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13
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Wahl AM, Yule DI. An inside job: Annexin 1A-Inositol 1,4,5-trisphosphate receptor interaction conveys endoplasmic reticulum luminal Ca 2+ sensitivity. Cell Calcium 2020; 90:102250. [PMID: 32668368 DOI: 10.1016/j.ceca.2020.102250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 07/01/2020] [Indexed: 10/23/2022]
Abstract
Cytoplasmic Ca2+ is a pivotal regulator of IP3R activity. It is however controversial whether the [Ca2+] in the Endoplasmic Reticulum lumen also directly regulates channel function. We highlight a recent paper that demonstrates that luminal [Ca2+] potently inhibits IP3R activity. This regulation occurs indirectly by an interaction mediated through a binding partner, likely Annexin 1A.
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Affiliation(s)
- Amanda M Wahl
- Department of Pharmacology and Physiology, University of Rochester, Rochester NY 14542, United States
| | - David I Yule
- Department of Pharmacology and Physiology, University of Rochester, Rochester NY 14542, United States.
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14
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Arige V, Yule DI. Pivotal role of type-1 inositol 1,4,5-trisphosphate receptor for glucagon-induced gluconeogenesis. Cell Calcium 2020; 90:102243. [PMID: 32562974 DOI: 10.1016/j.ceca.2020.102243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 06/08/2020] [Accepted: 06/08/2020] [Indexed: 10/24/2022]
Abstract
We highlight a recent paper which documents the important role that Ca2+ release through type-1 Inositol 1,4,5-trisphosphate receptor (IP3R1) plays in the acute regulation by glucagon of gluconeogenesis in hepatocytes. The specificity is likely the result of discrete localization close to mitochondria and PKA-dependent phosphorylation of IP3R1 which enhances Ca2+ release.
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Affiliation(s)
- Vikas Arige
- Department of Pharmacology and Physiology, University of Rochester, Rochester, NY, 14642, United States
| | - David I Yule
- Department of Pharmacology and Physiology, University of Rochester, Rochester, NY, 14642, United States.
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15
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Ahuja M, Chung WY, Lin WY, McNally BA, Muallem S. Ca 2+ Signaling in Exocrine Cells. Cold Spring Harb Perspect Biol 2020; 12:cshperspect.a035279. [PMID: 31636079 DOI: 10.1101/cshperspect.a035279] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Calcium (Ca2+) and cyclic AMP (cAMP) signaling cross talk and synergize to stimulate the cardinal functions of exocrine cells, regulated exocytosis, and fluid and electrolyte secretion. This physiological process requires the organization of the two signaling pathways into complexes at defined cellular domains and close placement. Such domains are formed by membrane contact sites (MCS). This review discusses the basic properties of Ca2+ signaling in exocrine cells, the role of MCS in the organization of cell signaling and in cross talk and synergism between the Ca2+ and cAMP signaling pathways and, finally, the mechanism by which the Ca2+ and cAMP pathways synergize to stimulate epithelial fluid and electrolyte secretion.
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Affiliation(s)
- Malini Ahuja
- Epithelial Signaling and Transport Section, National Institute of Dental and Craniofacial Research, National Institute of Health, Bethesda, Maryland 20892
| | - Woo Young Chung
- Epithelial Signaling and Transport Section, National Institute of Dental and Craniofacial Research, National Institute of Health, Bethesda, Maryland 20892
| | - Wei-Yin Lin
- Epithelial Signaling and Transport Section, National Institute of Dental and Craniofacial Research, National Institute of Health, Bethesda, Maryland 20892
| | - Beth A McNally
- Epithelial Signaling and Transport Section, National Institute of Dental and Craniofacial Research, National Institute of Health, Bethesda, Maryland 20892
| | - Shmuel Muallem
- Epithelial Signaling and Transport Section, National Institute of Dental and Craniofacial Research, National Institute of Health, Bethesda, Maryland 20892
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16
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Rosa N, Sneyers F, Parys JB, Bultynck G. Type 3 IP 3 receptors: The chameleon in cancer. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2020; 351:101-148. [PMID: 32247578 DOI: 10.1016/bs.ircmb.2020.02.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Inositol 1,4,5-trisphosphate (IP3) receptors (IP3Rs), intracellular calcium (Ca2+) release channels, fulfill key functions in cell death and survival processes, whose dysregulation contributes to oncogenesis. This is essentially due to the presence of IP3Rs in microdomains of the endoplasmic reticulum (ER) in close proximity to the mitochondria. As such, IP3Rs enable efficient Ca2+ transfers from the ER to the mitochondria, thus regulating metabolism and cell fate. This review focuses on one of the three IP3R isoforms, the type 3 IP3R (IP3R3), which is linked to proapoptotic ER-mitochondrial Ca2+ transfers. Alterations in IP3R3 expression have been highlighted in numerous cancer types, leading to dysregulations of Ca2+ signaling and cellular functions. However, the outcome of IP3R3-mediated Ca2+ transfers for mitochondrial function is complex with opposing effects on oncogenesis. IP3R3 can either suppress cancer by promoting cell death and cellular senescence or support cancer by driving metabolism, anabolic processes, cell cycle progression, proliferation and invasion. The aim of this review is to provide an overview of IP3R3 dysregulations in cancer and describe how such dysregulations alter critical cellular processes such as proliferation or cell death and survival. Here, we pose that the IP3R3 isoform is not only linked to proapoptotic ER-mitochondrial Ca2+ transfers but might also be involved in prosurvival signaling.
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Affiliation(s)
- Nicolas Rosa
- KU Leuven, Laboratory of Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine and Leuven Kanker Instituut (LKI), Leuven, Belgium
| | - Flore Sneyers
- KU Leuven, Laboratory of Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine and Leuven Kanker Instituut (LKI), Leuven, Belgium
| | - Jan B Parys
- KU Leuven, Laboratory of Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine and Leuven Kanker Instituut (LKI), Leuven, Belgium
| | - Geert Bultynck
- KU Leuven, Laboratory of Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine and Leuven Kanker Instituut (LKI), Leuven, Belgium.
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17
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Danese A, Marchi S, Vitto VAM, Modesti L, Leo S, Wieckowski MR, Giorgi C, Pinton P. Cancer-Related Increases and Decreases in Calcium Signaling at the Endoplasmic Reticulum-Mitochondria Interface (MAMs). Rev Physiol Biochem Pharmacol 2020; 185:153-193. [PMID: 32789789 DOI: 10.1007/112_2020_43] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Endoplasmic reticulum (ER)-mitochondria regions are specialized subdomains called also mitochondria-associated membranes (MAMs). MAMs allow regulation of lipid synthesis and represent hubs for ion and metabolite signaling. As these two organelles can module both the amplitude and the spatiotemporal patterns of calcium (Ca2+) signals, this particular interaction controls several Ca2+-dependent pathways well known for their contribution to tumorigenesis, such as metabolism, survival, sensitivity to cell death, and metastasis. Mitochondria-mediated apoptosis arises from mitochondrial Ca2+ overload, permeabilization of the mitochondrial outer membrane, and the release of mitochondrial apoptotic factors into the cytosol. Decreases in Ca2+ signaling at the ER-mitochondria interface are being studied in depth as failure of apoptotic-dependent cell death is one of the predominant characteristics of cancer cells. However, some recent papers that linked MAMs Ca2+ crosstalk-related upregulation to tumor onset and progression have aroused the interest of the scientific community.In this review, we will describe how different MAMs-localized proteins modulate the effectiveness of Ca2+-dependent apoptotic stimuli by causing both increases and decreases in the ER-mitochondria interplay and, specifically, by modulating Ca2+ signaling.
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Affiliation(s)
- Alberto Danese
- Department of Medical Sciences, Laboratory for Technologies of Advanced Therapies (LTTA), University of Ferrara, Ferrara, Italy
| | - Saverio Marchi
- Department of Clinical and Molecular Sciences, Marche Polytechnic University, Ancona, Italy
| | - Veronica Angela Maria Vitto
- Department of Medical Sciences, Laboratory for Technologies of Advanced Therapies (LTTA), University of Ferrara, Ferrara, Italy
| | - Lorenzo Modesti
- Department of Medical Sciences, Laboratory for Technologies of Advanced Therapies (LTTA), University of Ferrara, Ferrara, Italy
| | - Sara Leo
- Department of Medical Sciences, Laboratory for Technologies of Advanced Therapies (LTTA), University of Ferrara, Ferrara, Italy
| | - Mariusz R Wieckowski
- Laboratory of Mitochondrial Biology and Metabolism, Nencki Institute of Experimental Biology of Polish Academy of Sciences, Warsaw, Poland
| | - Carlotta Giorgi
- Department of Medical Sciences, Laboratory for Technologies of Advanced Therapies (LTTA), University of Ferrara, Ferrara, Italy
| | - Paolo Pinton
- Department of Medical Sciences, Laboratory for Technologies of Advanced Therapies (LTTA), University of Ferrara, Ferrara, Italy.
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18
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Conrard L, Tyteca D. Regulation of Membrane Calcium Transport Proteins by the Surrounding Lipid Environment. Biomolecules 2019; 9:E513. [PMID: 31547139 PMCID: PMC6843150 DOI: 10.3390/biom9100513] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 09/09/2019] [Accepted: 09/10/2019] [Indexed: 12/11/2022] Open
Abstract
Calcium ions (Ca2+) are major messengers in cell signaling, impacting nearly every aspect of cellular life. Those signals are generated within a wide spatial and temporal range through a large variety of Ca2+ channels, pumps, and exchangers. More and more evidences suggest that Ca2+ exchanges are regulated by their surrounding lipid environment. In this review, we point out the technical challenges that are currently being overcome and those that still need to be defeated to analyze the Ca2+ transport protein-lipid interactions. We then provide evidences for the modulation of Ca2+ transport proteins by lipids, including cholesterol, acidic phospholipids, sphingolipids, and their metabolites. We also integrate documented mechanisms involved in the regulation of Ca2+ transport proteins by the lipid environment. Those include: (i) Direct interaction inside the protein with non-annular lipids; (ii) close interaction with the first shell of annular lipids; (iii) regulation of membrane biophysical properties (e.g., membrane lipid packing, thickness, and curvature) directly around the protein through annular lipids; and (iv) gathering and downstream signaling of several proteins inside lipid domains. We finally discuss recent reports supporting the related alteration of Ca2+ and lipids in different pathophysiological events and the possibility to target lipids in Ca2+-related diseases.
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Affiliation(s)
- Louise Conrard
- CELL Unit, de Duve Institute and Université catholique de Louvain, UCL B1.75.05, avenue Hippocrate, 75, B-1200 Brussels, Belgium
| | - Donatienne Tyteca
- CELL Unit, de Duve Institute and Université catholique de Louvain, UCL B1.75.05, avenue Hippocrate, 75, B-1200 Brussels, Belgium.
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19
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Bartok A, Weaver D, Golenár T, Nichtova Z, Katona M, Bánsághi S, Alzayady KJ, Thomas VK, Ando H, Mikoshiba K, Joseph SK, Yule DI, Csordás G, Hajnóczky G. IP 3 receptor isoforms differently regulate ER-mitochondrial contacts and local calcium transfer. Nat Commun 2019; 10:3726. [PMID: 31427578 PMCID: PMC6700175 DOI: 10.1038/s41467-019-11646-3] [Citation(s) in RCA: 186] [Impact Index Per Article: 37.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Accepted: 07/12/2019] [Indexed: 12/31/2022] Open
Abstract
Contact sites of endoplasmic reticulum (ER) and mitochondria locally convey calcium signals between the IP3 receptors (IP3R) and the mitochondrial calcium uniporter, and are central to cell survival. It remains unclear whether IP3Rs also have a structural role in contact formation and whether the different IP3R isoforms have redundant functions. Using an IP3R-deficient cell model rescued with each of the three IP3R isoforms and an array of super-resolution and ultrastructural approaches we demonstrate that IP3Rs are required for maintaining ER-mitochondrial contacts. This role is independent of calcium fluxes. We also show that, while each isoform can support contacts, type 2 IP3R is the most effective in delivering calcium to the mitochondria. Thus, these studies reveal a non-canonical, structural role for the IP3Rs and direct attention towards the type 2 IP3R that was previously neglected in the context of ER-mitochondrial calcium signaling.
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Affiliation(s)
- Adam Bartok
- MitoCare Center, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA, USA
- Departent of Medical Biochemistry, Semmelweis University, Budapest, Hungary
| | - David Weaver
- MitoCare Center, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Tünde Golenár
- MitoCare Center, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Zuzana Nichtova
- MitoCare Center, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Máté Katona
- MitoCare Center, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Száva Bánsághi
- MitoCare Center, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Kamil J Alzayady
- Department of Physiology and Pharmacology, University of Rochester, Rochester, NY, USA
| | - V Kaye Thomas
- Department of Physiology and Pharmacology, University of Rochester, Rochester, NY, USA
| | - Hideaki Ando
- Lab for Developmental Neurobiology, RIKEN Brain Science Institute, Saitama, Japan
- Laboratory of Molecular Biomedicine for Pathogenesis, Center for Disease Biology and Integrative Medicine, Faculty of Medicine, The University of Tokyo 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Katsuhiko Mikoshiba
- Lab for Developmental Neurobiology, RIKEN Brain Science Institute, Saitama, Japan
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech University, 201210, Shanghai, China
| | - Suresh K Joseph
- MitoCare Center, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA, USA
| | - David I Yule
- Department of Physiology and Pharmacology, University of Rochester, Rochester, NY, USA
| | - György Csordás
- MitoCare Center, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA, USA.
| | - György Hajnóczky
- MitoCare Center, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA, USA.
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20
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Chen B, Qi CY, Chen L, Dai MJ, Miao YY, Chen R, Wei WE, Yang S, Wang HL, Duan XG, Gong MW, Wang Y, Xue ZF. A C1976Y missense mutation in the mouse Ip3r1 gene leads to short-term mydriasis and unfolded protein response in the iris constrictor muscles. Exp Anim 2019; 69:45-53. [PMID: 31391379 PMCID: PMC7004804 DOI: 10.1538/expanim.19-0007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Ip3r1 encodes an inositol 1,4,5-trisphosphate-responsive calcium
channel. Mutations in the IP3R1 gene in humans may cause Gillespie
syndrome (GS) typically presents as fixed dilated pupils in affected infants, which was
referred to as iris hypoplasia. However, there is no report of mice with
Ip3r1 heterozygous mutations showing dilated pupils. Here, we report a
new Ip3r1 allele with short-term dilated pupil phenotype derived from an
N-ethyl-N-nitrosourea (ENU) mutagenesis screen. This allele carries a G5927A transition
mutation in Ip3r1 gene (NM_010585), which is predicted to result in a
C1976Y amino acid change in the open reading frame of IP3R1 (NP_034715). We named this
novel Ip3r1 allele Ip3r1C1976Y. Histology and
pharmacological tests show that the dilated pupil phenotype is a mydriasis caused by the
functional defect in the iris constrictor muscles in
Ip3r1C1976Y. The dilated pupil phenotype in
Ip3r1C1976Y was referred to as mydriasis and excluding
iris hypoplasia. IHC analysis revealed increased expression of BIP protein, the master
regulator of unfolded protein response (UPR) signaling, in
Ip3r1C1976Y mice that did not recover. This study is the
first report of an Ip3r1 mutation being associated with the mydriasis
phenotype. Ip3r1C1976Y mice represent a self-healing model
that may be used to study the therapeutic approach for Ip3r1-related
diseases.
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Affiliation(s)
- Bing Chen
- Institute of Comparative Medicine, Yangzhou University, 12 Wenhui East Road, Yangzhou, Jiangsu Province 225009, P.R.China.,College of Veterinary Medicine, Yangzhou University, 12 Wenhui East Road, Yangzhou, Jiangsu Province 225009, P.R.China.,Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, 12 Wenhui East Road, Yangzhou, Jiangsu Province 225009, P.R.China
| | - Chong-Yang Qi
- College of Veterinary Medicine, Yangzhou University, 12 Wenhui East Road, Yangzhou, Jiangsu Province 225009, P.R.China
| | - Li Chen
- College of Veterinary Medicine, Yangzhou University, 12 Wenhui East Road, Yangzhou, Jiangsu Province 225009, P.R.China
| | - Meng-Jun Dai
- College of Veterinary Medicine, Yangzhou University, 12 Wenhui East Road, Yangzhou, Jiangsu Province 225009, P.R.China
| | - Ya-You Miao
- College of Veterinary Medicine, Yangzhou University, 12 Wenhui East Road, Yangzhou, Jiangsu Province 225009, P.R.China
| | - Rui Chen
- College of Veterinary Medicine, Yangzhou University, 12 Wenhui East Road, Yangzhou, Jiangsu Province 225009, P.R.China
| | - Wan-E Wei
- College of Veterinary Medicine, Yangzhou University, 12 Wenhui East Road, Yangzhou, Jiangsu Province 225009, P.R.China
| | - Shun Yang
- College of Veterinary Medicine, Yangzhou University, 12 Wenhui East Road, Yangzhou, Jiangsu Province 225009, P.R.China
| | - Hong-Ling Wang
- College of Veterinary Medicine, Yangzhou University, 12 Wenhui East Road, Yangzhou, Jiangsu Province 225009, P.R.China
| | - Xiao-Ge Duan
- College of Veterinary Medicine, Yangzhou University, 12 Wenhui East Road, Yangzhou, Jiangsu Province 225009, P.R.China
| | - Min-Wei Gong
- College of Veterinary Medicine, Yangzhou University, 12 Wenhui East Road, Yangzhou, Jiangsu Province 225009, P.R.China
| | - Yi Wang
- College of Veterinary Medicine, Yangzhou University, 12 Wenhui East Road, Yangzhou, Jiangsu Province 225009, P.R.China
| | - Zheng-Feng Xue
- Institute of Comparative Medicine, Yangzhou University, 12 Wenhui East Road, Yangzhou, Jiangsu Province 225009, P.R.China.,College of Veterinary Medicine, Yangzhou University, 12 Wenhui East Road, Yangzhou, Jiangsu Province 225009, P.R.China.,Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, 12 Wenhui East Road, Yangzhou, Jiangsu Province 225009, P.R.China
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21
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An element for development: Calcium signaling in mammalian reproduction and development. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2019; 1866:1230-1238. [DOI: 10.1016/j.bbamcr.2019.02.016] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 02/22/2019] [Accepted: 02/24/2019] [Indexed: 11/21/2022]
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22
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Potapenko E, Negrão NW, Huang G, Docampo R. The acidocalcisome inositol-1,4,5-trisphosphate receptor of Trypanosoma brucei is stimulated by luminal polyphosphate hydrolysis products. J Biol Chem 2019; 294:10628-10637. [PMID: 31138655 DOI: 10.1074/jbc.ra119.007906] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Revised: 05/27/2019] [Indexed: 12/21/2022] Open
Abstract
Acidocalcisomes are acidic calcium stores rich in polyphosphate (polyP) and are present in trypanosomes and also in a diverse range of other organisms. Ca2+ is released from these organelles through a channel, inositol 1,4,5-trisphosphate receptor (TbIP3R), which is essential for growth and infectivity of the parasite Trypanosoma brucei However, the mechanism by which TbIP3R controls Ca2+ release is unclear. In this work, we expressed TbIP3R in a chicken B lymphocyte cell line in which the genes for all three vertebrate IP3Rs were stably ablated (DT40-3KO). We show that IP3-mediated Ca2+ release depends on Ca2+ but not on ATP concentration and is inhibited by heparin, caffeine, and 2-aminomethoxydiphenyl borate (2-APB). Excised patch clamp recordings from nuclear membranes of DT40 cells expressing only TbIP3R disclosed that luminal inorganic orthophosphate (Pi) or pyrophosphate (PPi), and neutral or alkaline pH can stimulate IP3-generated currents. In contrast, polyP or acidic pH did not induce these currents, and nuclear membranes obtained from cells expressing rat IP3R were unresponsive to polyP or its hydrolysis products. Our results are consistent with the notion that polyP hydrolysis products within acidocalcisomes or alkalinization of their luminal pH activate TbIP3R and Ca2+ release. We conclude that TbIP3R is well-adapted to its role as the major Ca2+ release channel of acidocalcisomes in T. brucei.
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Affiliation(s)
| | - Núria W Negrão
- From the Center for Tropical and Emerging Global Diseases and.,Department of Cellular Biology, University of Georgia, Athens, Georgia 30602
| | - Guozhong Huang
- From the Center for Tropical and Emerging Global Diseases and
| | - Roberto Docampo
- From the Center for Tropical and Emerging Global Diseases and .,Department of Cellular Biology, University of Georgia, Athens, Georgia 30602
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23
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Wang L, Yule DI. Differential regulation of ion channels function by proteolysis. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2018; 1865:1698-1706. [PMID: 30009861 DOI: 10.1016/j.bbamcr.2018.07.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Revised: 07/06/2018] [Accepted: 07/10/2018] [Indexed: 12/23/2022]
Abstract
Ion channels are pore-forming protein complexes in membranes that play essential roles in a diverse array of biological activities. Ion channel activity is strictly regulated at multiple levels and by numerous cellular events to selectively activate downstream effectors involved in specific biological activities. For example, ions, binding proteins, nucleotides, phosphorylation, the redox state, channel subunit composition have all been shown to regulate channel activity and subsequently allow channels to participate in distinct cellular events. While these forms of modulation are well documented and have been extensively reviewed, in this article, we will first review and summarize channel proteolysis as a novel and quite widespread mechanism for altering channel activity. We will then highlight the recent findings demonstrating that proteolysis profoundly alters Inositol 1,4,5 trisphosphate receptor activity, and then discuss its potential functional ramifications in various developmental and pathological conditions.
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Affiliation(s)
- Liwei Wang
- Department of Pharmacology and Physiology, University of Rochester, Rochester, NY 14642, United States of America
| | - David I Yule
- Department of Pharmacology and Physiology, University of Rochester, Rochester, NY 14642, United States of America.
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24
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Wang L, Wagner LE, Alzayady KJ, Yule DI. Region-specific proteolysis differentially modulates type 2 and type 3 inositol 1,4,5-trisphosphate receptor activity in models of acute pancreatitis. J Biol Chem 2018; 293:13112-13124. [PMID: 29970616 DOI: 10.1074/jbc.ra118.003421] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Revised: 06/04/2018] [Indexed: 12/22/2022] Open
Abstract
Fine-tuning of the activity of inositol 1,4,5-trisphosphate receptors (IP3R) by a diverse array of regulatory inputs results in intracellular Ca2+ signals with distinct characteristics. These events allow the activation of specific downstream effectors. We reported previously that region-specific proteolysis represents a novel regulatory event for type 1 IP3R (R1). Specifically, caspase-fragmented R1 display a marked increase in single-channel open probability. More importantly, the distinct characteristics of the Ca2+ signals elicited via fragmented R1 can activate alternate downstream effectors. In this report, we expand these studies to investigate whether all IP3R subtypes are regulated by proteolysis. We now show that type 2 and type 3 IP3R (R2 and R3, respectively) are proteolytically cleaved in rodent models of acute pancreatitis. Surprisingly, fragmented IP3R retained tetrameric architecture, remained embedded in endoplasmic reticulum membranes and were not functionally disabled. Proteolysis was associated with a marked attenuation of the frequency of Ca2+ signals in pancreatic lobules. Consistent with these data, expression of DNAs encoding complementary R2 and R3 peptides mimicking fragmented receptors at particular sites, resulted in a significant decrease in the frequency of agonist-stimulated Ca2+ oscillations. Further, proteolysis of R2 resulted in a marked decrease in single-channel open probability. Taken together, proteolytic fragmentation modulates R2 and R3 activity in a region-specific manner, and this event may contribute to the altered Ca2+ signals in pancreatic acinar cells during acute pancreatitis.
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Affiliation(s)
- Liwei Wang
- From the Department of Pharmacology and Physiology, University of Rochester, Rochester, New York 14642
| | - Larry E Wagner
- From the Department of Pharmacology and Physiology, University of Rochester, Rochester, New York 14642
| | - Kamil J Alzayady
- From the Department of Pharmacology and Physiology, University of Rochester, Rochester, New York 14642
| | - David I Yule
- From the Department of Pharmacology and Physiology, University of Rochester, Rochester, New York 14642
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25
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Wang L, Wagner LE, Alzayady KJ, Yule DI. Region-specific proteolysis differentially regulates type 1 inositol 1,4,5-trisphosphate receptor activity. J Biol Chem 2017; 292:11714-11726. [PMID: 28526746 DOI: 10.1074/jbc.m117.789917] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Revised: 05/11/2017] [Indexed: 12/31/2022] Open
Abstract
The inositol 1,4,5 trisphosphate receptor (IP3R) is an intracellular Ca2+ release channel expressed predominately on the membranes of the endoplasmic reticulum. IP3R1 can be cleaved by caspase or calpain into at least two receptor fragments. However, the functional consequences of receptor fragmentation are poorly understood. Our previous work has demonstrated that IP3R1 channels, formed following either enzymatic fragmentation or expression of the corresponding complementary polypeptide chains, retain tetrameric architecture and are still activated by IP3 binding despite the loss of peptide continuity. In this study, we demonstrate that region-specific receptor fragmentation modifies channel regulation. Specifically, the agonist-evoked temporal Ca2+ release profile and protein kinase A modulation of Ca2+ release are markedly altered. Moreover, we also demonstrate that activation of fragmented IP3R1 can result in a distinct functional outcome. Our work suggests that proteolysis of IP3R1 may represent a novel form of modulation of IP3R1 channel function and increases the repertoire of Ca2+ signals achievable through this channel.
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Affiliation(s)
- Liwei Wang
- Department of Pharmacology and Physiology, University of Rochester, Rochester, New York 14642
| | - Larry E Wagner
- Department of Pharmacology and Physiology, University of Rochester, Rochester, New York 14642
| | - Kamil J Alzayady
- Department of Pharmacology and Physiology, University of Rochester, Rochester, New York 14642
| | - David I Yule
- Department of Pharmacology and Physiology, University of Rochester, Rochester, New York 14642.
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Bueno Bergantin L. Novel Challenges for the Therapeutics of Depression: Pharmacological Modulation of Interaction between the Intracellular Signaling Pathways Mediated by Ca2+ and cAMP. JOURNAL OF ADDICTION THERAPY AND RESEARCH 2017; 1:001-006. [DOI: 10.29328/journal.jatr.1001001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/03/2024]
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27
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Garcia MI, Boehning D. Cardiac inositol 1,4,5-trisphosphate receptors. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2016; 1864:907-914. [PMID: 27884701 DOI: 10.1016/j.bbamcr.2016.11.017] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Revised: 11/16/2016] [Accepted: 11/16/2016] [Indexed: 10/20/2022]
Abstract
Calcium is a second messenger that regulates almost all cellular functions. In cardiomyocytes, calcium plays an integral role in many functions including muscle contraction, gene expression, and cell death. Inositol 1,4,5-trisphosphate receptors (IP3Rs) are a family of calcium channels that are ubiquitously expressed in all tissues. In the heart, IP3Rs have been associated with regulation of cardiomyocyte function in response to a variety of neurohormonal agonists, including those implicated in cardiac disease. Notably, IP3R activity is thought to be essential for mediating the hypertrophic response to multiple stimuli including endothelin-1 and angiotensin II. In this review, we will explore the functional implications of IP3R activity in the heart in health and disease.
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Affiliation(s)
- M Iveth Garcia
- Cell Biology Graduate Program, University of Texas Medical Branch, Galveston, TX 77555, United States; Department of Biochemistry and Molecular Biology, McGovern Medical School at UTHealth, Houston, TX 77030, United States
| | - Darren Boehning
- Department of Biochemistry and Molecular Biology, McGovern Medical School at UTHealth, Houston, TX 77030, United States.
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Bergantin LB, Caricati-Neto A. Challenges for the pharmacological treatment of neurological and psychiatric disorders: Implications of the Ca(2+)/cAMP intracellular signalling interaction. Eur J Pharmacol 2016; 788:255-260. [PMID: 27349146 DOI: 10.1016/j.ejphar.2016.06.034] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Revised: 06/15/2016] [Accepted: 06/21/2016] [Indexed: 11/15/2022]
Abstract
In 2013, we discovered that the entitled "calcium paradox" phenomenon, which means a paradoxical sympathetic hyperactivity produced by l-type Ca(2+) channel blockers (CCBs), used in antihypertensive therapy, is due to interaction between the intracellular signalling pathways mediated by Ca(2+) and cAMP (Ca(2+)/cAMP interaction). In 2015, we proposed that the pharmacological manipulation of this interaction could be a new therapeutic strategy for increasing neurotransmission in psychiatric disorders, and producing neuroprotection in the neurodegenerative diseases. Besides the paradoxical sympathetic hyperactivity produced by CCBs, several clinical studies have been demonstrating pleiotropic effects of CCBs, including neuroprotective effects. CCBs genuinely exhibit cognitive-enhancing abilities and reduce the risk of dementia, including Alzheimer's, Parkinson´s disease and others. The molecular mechanisms involved in these pleiotropic effects remain under debate. Our recent discovery that the "calcium paradox" phenomenon is due to Ca(2+)/cAMP interaction may provide new insights for the pharmacological treatment of neurological and psychiatric disorders, including enhancement of current therapies mainly by reducing adverse effects, and improving effectiveness of modern medicines. Whether Ca(2+)/cAMP interaction is involved in CCBs pleiotropic effects also deserves special attention. Then, the pharmacological manipulation of the Ca(2+)/cAMP interaction could be a more efficient therapeutic strategy for increasing neurotransmission in psychiatric disorders, and producing neuroprotection in the neurodegenerative diseases. Thus, in this review we summarize the current knowledge of this field, making new directions and future perspectives.
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Affiliation(s)
- Leandro Bueno Bergantin
- Department of Pharmacology, Universidade Federal de São Paulo, Escola Paulista de Medicina, Laboratory of Autonomic and Cardiovascular Pharmacology, 55 11 5576-4973, Rua Pedro de Toledo, 669, Vila Clementino, São Paulo, SP CEP 04039-032, Brazil.
| | - Afonso Caricati-Neto
- Department of Pharmacology, Universidade Federal de São Paulo, Escola Paulista de Medicina, Laboratory of Autonomic and Cardiovascular Pharmacology, 55 11 5576-4973, Rua Pedro de Toledo, 669, Vila Clementino, São Paulo, SP CEP 04039-032, Brazil
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Gerber S, Alzayady K, Burglen L, Brémond-Gignac D, Marchesin V, Roche O, Rio M, Funalot B, Calmon R, Durr A, Gil-da-Silva-Lopes V, Ribeiro Bittar M, Orssaud C, Héron B, Ayoub E, Berquin P, Bahi-Buisson N, Bole C, Masson C, Munnich A, Simons M, Delous M, Dollfus H, Boddaert N, Lyonnet S, Kaplan J, Calvas P, Yule D, Rozet JM, Fares Taie L. Recessive and Dominant De Novo ITPR1 Mutations Cause Gillespie Syndrome. Am J Hum Genet 2016; 98:971-980. [PMID: 27108797 DOI: 10.1016/j.ajhg.2016.03.004] [Citation(s) in RCA: 105] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Accepted: 03/07/2016] [Indexed: 12/01/2022] Open
Abstract
Gillespie syndrome (GS) is a rare variant form of aniridia characterized by non-progressive cerebellar ataxia, intellectual disability, and iris hypoplasia. Unlike the more common dominant and sporadic forms of aniridia, there has been no significant association with PAX6 mutations in individuals with GS and the mode of inheritance of the disease had long been regarded as uncertain. Using a combination of trio-based whole-exome sequencing and Sanger sequencing in five simplex GS-affected families, we found homozygous or compound heterozygous truncating mutations (c.4672C>T [p.Gln1558(∗)], c.2182C>T [p.Arg728(∗)], c.6366+3A>T [p.Gly2102Valfs5(∗)], and c.6664+5G>T [p.Ala2221Valfs23(∗)]) and de novo heterozygous mutations (c.7687_7689del [p.Lys2563del] and c.7659T>G [p.Phe2553Leu]) in the inositol 1,4,5-trisphosphate receptor type 1 gene (ITPR1). ITPR1 encodes one of the three members of the IP3-receptors family that form Ca(2+) release channels localized predominantly in membranes of endoplasmic reticulum Ca(2+) stores. The truncation mutants, which encompass the IP3-binding domain and varying lengths of the modulatory domain, did not form functional channels when produced in a heterologous cell system. Furthermore, ITPR1 p.Lys2563del mutant did not form IP3-induced Ca(2+) channels but exerted a negative effect when co-produced with wild-type ITPR1 channel activity. In total, these results demonstrate biallelic and monoallelic ITPR1 mutations as the underlying genetic defects for Gillespie syndrome, further extending the spectrum of ITPR1-related diseases.
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The Regulatory Role of Rolipram on Inflammatory Mediators and Cholinergic/Adrenergic Stimulation-Induced Signals in Isolated Primary Mouse Submandibular Gland Cells. Mediators Inflamm 2016; 2016:3745961. [PMID: 27143817 PMCID: PMC4838792 DOI: 10.1155/2016/3745961] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Revised: 03/17/2016] [Accepted: 03/20/2016] [Indexed: 12/27/2022] Open
Abstract
Exposure to bacterial lipopolysaccharides (LPS) induces inflammatory signals in salivary glands. We investigated the regulatory role of phosphodiesterase 4 (PDE4) inhibitor rolipram on inflammatory mediators and cholinergic/adrenergic stimulation-induced intracellular Ca(2+) signaling in salivary acinar and ductal cells. Submandibular gland (SMG) expressed PDE4A through 4D mRNA and PDE4 was localized in the luminal membrane of SMG. LPS induced Ca(2+) signaling and ROS production in SMG. Treatment with rolipram blocked LPS-induced Ca(2+) increase and ROS production. The application of histamine evoked Ca(2+) signals and ROS production, which were attenuated by rolipram in SMG cells. Moreover, LPS-induced NLRP3 inflammasome and cleaved caspase-1 were inhibited by rolipram. The inhibitory role of rolipram in ROS-induced Ca(2+) signaling was mainly observed in acinar cells and not in ductal cells. Rolipram also protected SMG acinar but not ductal cells from LPS-induced cell membrane damage. In the case of cholinergic/adrenergic stimulation, carbachol/isoproterenol-induced Ca(2+) signals were upregulated by the treatment of rolipram in SMG. In the case of cAMP-dependent ductal bicarbonate secretion by rolipram, no effect was observed on the modulation of ductal chloride/bicarbonate exchange activity. Rolipram could suppress the inflammatory signals and could be a potential therapeutic strategy against LPS-induced inflammation to protect the salivary gland cells.
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Alzayady KJ, Wang L, Chandrasekhar R, Wagner LE, Van Petegem F, Yule DI. Defining the stoichiometry of inositol 1,4,5-trisphosphate binding required to initiate Ca2+ release. Sci Signal 2016; 9:ra35. [PMID: 27048566 DOI: 10.1126/scisignal.aad6281] [Citation(s) in RCA: 130] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Inositol 1,4,5-trisphosphate (IP3) receptors (IP3Rs) are tetrameric intracellular Ca(2+)-release channels with each subunit containing a binding site for IP3in the amino terminus. We provide evidence that four IP3molecules are required to activate the channel under diverse conditions. Comparing the concentration-response relationship for binding and Ca(2+)release suggested that IP3Rs are maximally occupied by IP3before substantial Ca(2+)release occurs. We showed that ligand binding-deficient subunits acted in a dominant-negative manner when coexpressed with wild-type monomers in the chicken immune cell line DT40-3KO, which lacks all three genes encoding IP3R subunits, and confirmed the same effect in an IP3R-null human cell line (HEK-3KO) generated by CRISPR/Cas9 technology. Using dimeric and tetrameric concatenated IP3Rs with increasing numbers of binding-deficient subunits, we addressed the obligate ligand stoichiometry. The concatenated IP3Rs with four ligand-binding sites exhibited Ca(2+)release and electrophysiological properties of native IP3Rs. However, IP3failed to activate IP3Rs assembled from concatenated dimers consisting of one binding-competent and one binding-deficient mutant subunit. Similarly, IP3Rs containing two monomers of IP3R2short, an IP3binding-deficient splice variant, were nonfunctional. Concatenated tetramers containing only three binding-competent ligand-binding sites were nonfunctional under a wide range of activating conditions. These data provide definitive evidence that IP3-induced Ca(2+)release only occurs when each IP3R monomer within the tetramer is occupied by IP3, thereby ensuring fidelity of Ca(2+)release.
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Affiliation(s)
- Kamil J Alzayady
- Department of Pharmacology and Physiology, University of Rochester, Rochester, NY 14642, USA
| | - Liwei Wang
- Department of Pharmacology and Physiology, University of Rochester, Rochester, NY 14642, USA
| | - Rahul Chandrasekhar
- Department of Pharmacology and Physiology, University of Rochester, Rochester, NY 14642, USA
| | - Larry E Wagner
- Department of Pharmacology and Physiology, University of Rochester, Rochester, NY 14642, USA
| | - Filip Van Petegem
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - David I Yule
- Department of Pharmacology and Physiology, University of Rochester, Rochester, NY 14642, USA.
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Chandrasekhar R, Alzayady KJ, Wagner LE, Yule DI. Unique Regulatory Properties of Heterotetrameric Inositol 1,4,5-Trisphosphate Receptors Revealed by Studying Concatenated Receptor Constructs. J Biol Chem 2016; 291:4846-60. [PMID: 26755721 DOI: 10.1074/jbc.m115.705301] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Indexed: 02/02/2023] Open
Abstract
The ability of inositol 1,4,5-trisphosphate receptors (IP3R) to precisely initiate and generate a diverse variety of intracellular Ca(2+) signals is in part mediated by the differential regulation of the three subtypes (R1, R2, and R3) by key functional modulators (IP3, Ca(2+), and ATP). However, the contribution of IP3R heterotetramerization to Ca(2+) signal diversity has largely been unexplored. In this report, we provide the first definitive biochemical evidence of endogenous heterotetramer formation. Additionally, we examine the contribution of individual subtypes within defined concatenated heterotetramers to the shaping of Ca(2+) signals. Under conditions where key regulators of IP3R function are optimal for Ca(2+) release, we demonstrate that individual monomers within heteromeric IP3Rs contributed equally toward generating a distinct 'blended' sensitivity to IP3 that is likely dictated by the unique IP3 binding affinity of the heteromers. However, under suboptimal conditions where [ATP] were varied, we found that one subtype dictated the ATP regulatory properties of heteromers. We show that R2 monomers within a heterotetramer were both necessary and sufficient to dictate the ATP regulatory properties. Finally, the ATP-binding site B in R2 critical for ATP regulation was mutated and rendered non-functional to address questions relating to the stoichiometry of IP3R regulation. Two intact R2 monomers were sufficient to maintain ATP regulation in R2 homotetramers. In summary, we demonstrate that heterotetrameric IP3R do not necessarily behave as the sum of the constituent subunits, and these properties likely extend the versatility of IP3-induced Ca(2+) signaling in cells expressing multiple IP3R isoforms.
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Affiliation(s)
- Rahul Chandrasekhar
- From the Department of Pharmacology and Physiology, University of Rochester, Rochester, New York 14642
| | - Kamil J Alzayady
- From the Department of Pharmacology and Physiology, University of Rochester, Rochester, New York 14642
| | - Larry E Wagner
- From the Department of Pharmacology and Physiology, University of Rochester, Rochester, New York 14642
| | - David I Yule
- From the Department of Pharmacology and Physiology, University of Rochester, Rochester, New York 14642
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Son A, Park S, Shin DM, Muallem S. Orai1 and STIM1 in ER/PM junctions: roles in pancreatic cell function and dysfunction. Am J Physiol Cell Physiol 2016; 310:C414-22. [PMID: 26739495 DOI: 10.1152/ajpcell.00349.2015] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Membrane contact sites (MCS) are critical junctions that form between the endoplasmic reticulum (ER) and membranes of various organelles, including the plasma membrane (PM). Signaling complexes, including mediators of Ca(2+) signaling, are assembled within MCS, such as the ER/PM junction. This is most evident in polarized epithelial cells, such as pancreatic cells. Core Ca(2+) signaling proteins cluster at the apical pole, the site of inositol 1,4,5-trisphosphate-mediated Ca(2+) release and Orai1/transient receptor potential canonical-mediated store-dependent Ca(2+) entry. Recent advances have characterized the proteins that tether the membranes at MCS and the role of these proteins in modulating physiological and pathological intracellular signaling. This review discusses recent advances in the characterization of Ca(2+) signaling at ER/PM junctions and the relation of these junctions to physiological and pathological Ca(2+) signaling in pancreatic acini.
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Affiliation(s)
- Aran Son
- Epithelial Signaling and Transport Section, Molecular Physiology and Therapeutics Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, Maryland
| | - Seonghee Park
- Department of Physiology, School of Medicine, Ewha Womans University, Seoul, Korea
| | - Dong Min Shin
- Department of Oral Biology, BK 21 PLUS Project, Yonsei University College of Dentistry, Seoul, Korea
| | - Shmuel Muallem
- Epithelial Signaling and Transport Section, Molecular Physiology and Therapeutics Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, Maryland;
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34
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Wang L, Alzayady KJ, Yule DI. Proteolytic fragmentation of inositol 1,4,5-trisphosphate receptors: a novel mechanism regulating channel activity? J Physiol 2015; 594:2867-76. [PMID: 26486785 DOI: 10.1113/jp271140] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2015] [Accepted: 09/30/2015] [Indexed: 12/15/2022] Open
Abstract
Inositol 1,4,5-trisphosphate receptors (IP3 Rs) are a family of ubiquitously expressed intracellular Ca(2+) release channels. Regulation of channel activity by Ca(2+) , nucleotides, phosphorylation, protein binding partners and other cellular factors is thought to play a major role in defining the specific spatiotemporal characteristics of intracellular Ca(2+) signals. These properties are, in turn, believed pivotal for the selective and specific physiological activation of Ca(2+) -dependent effectors. IP3 Rs are also substrates for the intracellular cysteine proteases, calpain and caspase. Cleavage of the IP3 R has been proposed to play a role in apoptotic cell death by uncoupling regions important for IP3 binding from the channel domain, leaving an unregulated leaky Ca(2+) pore. Contrary to this hypothesis, we demonstrate following proteolysis that N- and C-termini of IP3 R1 remain associated, presumably through non-covalent interactions. Further, we show that complementary fragments of IP3 R1 assemble into tetrameric structures and retain their ability to be regulated robustly by IP3 . While peptide continuity is clearly not necessary for IP3 -gating of the channel, we propose that cleavage of the IP3 R peptide chain may alter other important regulatory events to modulate channel activity. In this scenario, stimulation of the cleaved IP3 R may support distinct spatiotemporal Ca(2+) signals and activation of specific effectors. Notably, in many adaptive physiological events, the non-apoptotic activities of caspase and calpain are demonstrated to be important, but the substrates of the proteases are poorly defined. We speculate that proteolytic fragmentation may represent a novel form of IP3 R regulation, which plays a role in varied adaptive physiological processes.
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Affiliation(s)
- Liwei Wang
- Department of Pharmacology and Physiology, University of Rochester, 601 Elmwood Avenue, Rochester, NY, 14642, USA
| | - Kamil J Alzayady
- Department of Pharmacology and Physiology, University of Rochester, 601 Elmwood Avenue, Rochester, NY, 14642, USA
| | - David I Yule
- Department of Pharmacology and Physiology, University of Rochester, 601 Elmwood Avenue, Rochester, NY, 14642, USA
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Cao X, Choi S, Maléth JJ, Park S, Ahuja M, Muallem S. The ER/PM microdomain, PI(4,5)P₂ and the regulation of STIM1-Orai1 channel function. Cell Calcium 2015; 58:342-8. [PMID: 25843208 PMCID: PMC4564333 DOI: 10.1016/j.ceca.2015.03.003] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2015] [Revised: 03/06/2015] [Accepted: 03/09/2015] [Indexed: 12/18/2022]
Abstract
All forms of cell signaling occur in discreet cellular microdomains in which the ER is the main participant and include microdomains formed by the ER with lysosomes, endosomes, the nucleus, mitochondria and the plasma membrane. In the microdomains the two opposing organelles transfer and exchange constituents including lipids and ions. As is the case for other forms of signaling pathways, many components of the receptor-evoked Ca(2+) signal are clustered at the ER/PM microdomain, including the Orai1-STIM1 complex. This review discusses recent advances in understanding the molecular components that tether the ER and plasma membrane to form the ER/PM microdomains in which PI(4,5)P2 is enriched, and how dynamic targeting of the Orai1-STIM1 complex to PI(4,5)P2-poor and PI(4,5)P2-rich microdomains controls the activity of Orai1 and its regulation by Ca(2+) that is mediated by SARAF.
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Affiliation(s)
- Xu Cao
- Epithelial Signaling and Transport Section, Molecular Physiology and Therapeutics Branch, NIDCR, NIH, Bethesda, MD 20892, United States
| | - Seok Choi
- Department of Physiology, College of Medicine, Chosun University, 501-375, Republic of Korea
| | - Jozsef J Maléth
- First Department of Medicine, University of Szeged, Szeged H-6725, Hungary
| | - Seonghee Park
- Department of Physiology, School of Medicine, Ewha Womans University, 911-1 Mok-6-dong, Yang Chun-gu, Seoul 158-710, Republic of Korea
| | - Malini Ahuja
- Epithelial Signaling and Transport Section, Molecular Physiology and Therapeutics Branch, NIDCR, NIH, Bethesda, MD 20892, United States
| | - Shmuel Muallem
- Epithelial Signaling and Transport Section, Molecular Physiology and Therapeutics Branch, NIDCR, NIH, Bethesda, MD 20892, United States.
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Caricati-Neto A, García AG, Bergantin LB. Pharmacological implications of the Ca(2+)/cAMP signaling interaction: from risk for antihypertensive therapy to potential beneficial for neurological and psychiatric disorders. Pharmacol Res Perspect 2015; 3:e00181. [PMID: 26516591 PMCID: PMC4618650 DOI: 10.1002/prp2.181] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Accepted: 08/10/2015] [Indexed: 11/25/2022] Open
Abstract
In this review, we discussed pharmacological implications of the Ca2+/cAMP signaling interaction in the antihypertensive and neurological/psychiatric disorders therapies. Since 1975, several clinical studies have reported that acute and chronic administration of L-type voltage-activated Ca2+ channels (VACCs) blockers, such as nifedipine, produces reduction in peripheral vascular resistance and arterial pressure associated with an increase in plasma noradrenaline levels and heart rate, typical of sympathetic hyperactivity. Despite this sympathetic hyperactivity has been initially attributed to adjust reflex of arterial pressure, the cellular and molecular mechanisms involved in this apparent sympathomimetic effect of the L-type VACCs blockers remained unclear for decades. In addition, experimental studies using isolated tissues richly innervated by sympathetic nerves (to exclude the influence of adjusting reflex) showed that neurogenic responses were completely inhibited by L-type VACCs blockers in concentrations above 1 μmol/L, but paradoxically potentiated in concentrations below 1 μmol/L. During almost four decades, these enigmatic phenomena remained unclear. In 2013, we discovered that this paradoxical increase in sympathetic activity produced by L-type VACCs blocker is due to interaction of the Ca2+/cAMP signaling pathways. Then, the pharmacological manipulation of the Ca2+/cAMP interaction produced by combination of the L-type VACCs blockers used in the antihypertensive therapy, and cAMP accumulating compounds used in the antidepressive therapy, could represent a potential cardiovascular risk for hypertensive patients due to increase in sympathetic hyperactivity. In contrast, this pharmacological manipulation could be a new therapeutic strategy for increasing neurotransmission in psychiatric disorders, and producing neuroprotection in the neurodegenerative diseases.
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Affiliation(s)
- Afonso Caricati-Neto
- Department of Pharmacology, Universidade Federal de São Paulo, Escola Paulista de Medicina São Paulo, Brazil
| | - Antonio G García
- Instituto Teófilo Hernando de I+D del Medicamento, Universidad Autónoma de Madrid Madrid, Spain
| | - Leandro Bueno Bergantin
- Department of Pharmacology, Universidade Federal de São Paulo, Escola Paulista de Medicina São Paulo, Brazil
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Correia J, Michelangeli F, Publicover S. Regulation and roles of Ca2+ stores in human sperm. Reproduction 2015; 150:R65-76. [PMID: 25964382 PMCID: PMC4497595 DOI: 10.1530/rep-15-0102] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Accepted: 05/11/2015] [Indexed: 12/16/2022]
Abstract
[Ca(2)(+)]i signalling is a key regulatory mechanism in sperm function. In mammalian sperm the Ca(2)(+)-permeable plasma membrane ion channel CatSper is central to [Ca(2)(+)]i signalling, but there is good evidence that Ca(2)(+) stored in intracellular organelles is also functionally important. Here we briefly review the current understanding of the diversity of Ca(2)(+) stores and the mechanisms for the regulation of their activity. We then consider the evidence for the involvement of these stores in [Ca(2)(+)]i signalling in mammalian (primarily human) sperm, the agonists that may activate these stores and their role in control of sperm function. Finally we consider the evidence that membrane Ca(2)(+) channels and stored Ca(2)(+) may play discrete roles in the regulation of sperm activities and propose a mechanism by which these different components of the sperm Ca(2)(+)-signalling apparatus may interact to generate complex and spatially diverse [Ca(2)(+)]i signals.
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Affiliation(s)
- Joao Correia
- School of BiosciencesUniversity of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | | | - Stephen Publicover
- School of BiosciencesUniversity of Birmingham, Edgbaston, Birmingham B15 2TT, UK
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Alzayady KJ, Sebé-Pedrós A, Chandrasekhar R, Wang L, Ruiz-Trillo I, Yule DI. Tracing the Evolutionary History of Inositol, 1, 4, 5-Trisphosphate Receptor: Insights from Analyses of Capsaspora owczarzaki Ca2+ Release Channel Orthologs. Mol Biol Evol 2015; 32:2236-53. [PMID: 25911230 DOI: 10.1093/molbev/msv098] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Cellular Ca(2+) homeostasis is tightly regulated and is pivotal to life. Inositol 1,4,5-trisphosphate receptors (IP3Rs) and ryanodine receptors (RyRs) are the major ion channels that regulate Ca(2+) release from intracellular stores. Although these channels have been extensively investigated in multicellular organisms, an appreciation of their evolution and the biology of orthologs in unicellular organisms is largely lacking. Extensive phylogenetic analyses reveal that the IP3R gene superfamily is ancient and diverged into two subfamilies, IP3R-A and IP3R-B/RyR, at the dawn of Opisthokonta. IP3R-B/RyR further diversified into IP3R-B and RyR at the stem of Filozoa. Subsequent evolution and speciation of Holozoa is associated with duplication of IP3R-A and RyR genes, and loss of IP3R-B in the vertebrate lineages. To gain insight into the properties of IP3R important for the challenges of multicellularity, the IP3R-A and IP3R-B family orthologs were cloned from Capsaspora owczarzaki, a close unicellular relative to Metazoa (designated as CO.IP3R-A and CO.IP3R-B). Both proteins were targeted to the endoplasmic reticulum. However, CO.IP3R-A, but strikingly not CO.IP3R-B, bound IP3, exhibited robust Ca(2+) release activity and associated with mammalian IP3Rs. These data indicate strongly that CO.IP3R-A as an exemplar of ancestral IP3R-A orthologs forms bona fide IP3-gated channels. Notably, however, CO.IP3R-A appears not to be regulated by Ca(2+), ATP or Protein kinase A-phosphorylation. Collectively, our findings explore the origin, conservation, and diversification of IP3R gene families and provide insight into the functionality of ancestral IP3Rs and the added specialization of these proteins in Metazoa.
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Affiliation(s)
- Kamil J Alzayady
- Department of Pharmacology and Physiology, University of Rochester
| | - Arnau Sebé-Pedrós
- Institut de Biologia Evolutiva, Universitat Pompeu Fabra-CSIC, Barcelona, Catalonia, Spain
| | | | - Liwei Wang
- Department of Pharmacology and Physiology, University of Rochester
| | - Iñaki Ruiz-Trillo
- Institut de Biologia Evolutiva, Universitat Pompeu Fabra-CSIC, Barcelona, Catalonia, Spain Departament de Genètica, Universitat de Barcelona, Barcelona, Catalonia, Spain Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Catalonia, Spain
| | - David I Yule
- Department of Pharmacology and Physiology, University of Rochester
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Shah SZA, Zhao D, Khan SH, Yang L. Regulatory Mechanisms of Endoplasmic Reticulum Resident IP3 Receptors. J Mol Neurosci 2015; 56:938-948. [PMID: 25859934 DOI: 10.1007/s12031-015-0551-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Accepted: 03/23/2015] [Indexed: 11/25/2022]
Abstract
Dysregulated calcium signaling and accumulation of aberrant proteins causing endoplasmic reticulum stress are the early sign of intra-axonal pathological events in many neurodegenerative diseases, and apoptotic signaling is initiated when the stress goes beyond the maximum threshold level of endoplasmic reticulum. The fate of the cell to undergo apoptosis is controlled by Ca2(+) signaling and dynamics at the level of the endoplasmic reticulum. Endoplasmic reticulum resident inositol 1,4,5-trisphosphate receptors (IP3R) play a pivotal role in cell death signaling by mediating Ca2(+) flux from the endoplasmic reticulum into the cytosol and mitochondria. Hence, many prosurvival and prodeath signaling pathways and proteins affect Ca2(+) signaling by directly targeting IP3R channels, which can happen in an IP3R-isoform-dependent manner. Here, in this review, we summarize the regulatory mechanisms of inositol triphosphate receptors in calcium regulation and initiation of apoptosis during unfolded protein response.
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Affiliation(s)
- Syed Zahid Ali Shah
- State Key Laboratories for Agrobiotechnology, Key Lab of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China
| | - Deming Zhao
- State Key Laboratories for Agrobiotechnology, Key Lab of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China
| | - Sher Hayat Khan
- State Key Laboratories for Agrobiotechnology, Key Lab of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China
| | - Lifeng Yang
- State Key Laboratories for Agrobiotechnology, Key Lab of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China.
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Mak DOD, Foskett JK. Inositol 1,4,5-trisphosphate receptors in the endoplasmic reticulum: A single-channel point of view. Cell Calcium 2014; 58:67-78. [PMID: 25555684 DOI: 10.1016/j.ceca.2014.12.008] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2014] [Revised: 12/09/2014] [Accepted: 12/10/2014] [Indexed: 10/24/2022]
Abstract
As an intracellular Ca(2+) release channel at the endoplasmic reticulum membrane, the ubiquitous inositol 1,4,5-trisphosphate (InsP3) receptor (InsP3R) plays a crucial role in the generation, propagation and regulation of intracellular Ca(2+) signals that regulate numerous physiological and pathophysiological processes. This review provides a concise account of the fundamental single-channel properties of the InsP3R channel: its conductance properties and its regulation by InsP3 and Ca(2+), its physiological ligands, studied using nuclear patch clamp electrophysiology.
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Affiliation(s)
- Don-On Daniel Mak
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, United States.
| | - J Kevin Foskett
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, United States; Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, United States
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Vervloessem T, Yule DI, Bultynck G, Parys JB. The type 2 inositol 1,4,5-trisphosphate receptor, emerging functions for an intriguing Ca²⁺-release channel. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2014; 1853:1992-2005. [PMID: 25499268 DOI: 10.1016/j.bbamcr.2014.12.006] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2014] [Revised: 12/02/2014] [Accepted: 12/03/2014] [Indexed: 12/19/2022]
Abstract
The inositol 1,4,5-trisphosphate (IP3) receptor (IP3R) type 2 (IP3R2) is an intracellular Ca²⁺-release channel located on the endoplasmic reticulum (ER). IP3R2 is characterized by a high sensitivity to both IP3 and ATP and is biphasically regulated by Ca²⁺. Furthermore, IP3R2 is modulated by various protein kinases. In addition to its regulation by protein kinase A, IP3R2 forms a complex with adenylate cyclase 6 and is directly regulated by cAMP. Finally, in the ER, IP3R2 is less mobile than the other IP3R isoforms, while its functional properties appear dominant in heterotetramers. These properties make the IP3R2 a Ca²⁺ channel with exquisite properties for setting up intracellular Ca²⁺ signals with unique characteristics. IP3R2 plays a crucial role in the function of secretory cell types (e.g. pancreatic acinar cells, hepatocytes, salivary gland, eccrine sweat gland). In cardiac myocytes, the role of IP3R2 appears more complex, because, together with IP3R1, it is needed for normal cardiogenesis, while its aberrant activity is implicated in cardiac hypertrophy and arrhythmias. Most importantly, its high sensitivity to IP3 makes IP3R2 a target for anti-apoptotic proteins (e.g. Bcl-2) in B-cell cancers. Disrupting IP3R/Bcl-2 interaction therefore leads in those cells to increased Ca²⁺ release and apoptosis. Intriguingly, IP3R2 is not only implicated in apoptosis but also in the induction of senescence, another tumour-suppressive mechanism. These results were the first to unravel the physiological and pathophysiological role of IP3R2 and we anticipate that further progress will soon be made in understanding the function of IP3R2 in various tissues and organs.
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Affiliation(s)
- Tamara Vervloessem
- KU Leuven, Laboratory of Molecular and Cellular Signalling, Department of Cellular and Molecular Medicine, Leuven, Belgium
| | - David I Yule
- University of Rochester, Department of Pharmacology and Physiology, Rochester, NY, USA
| | - Geert Bultynck
- KU Leuven, Laboratory of Molecular and Cellular Signalling, Department of Cellular and Molecular Medicine, Leuven, Belgium
| | - Jan B Parys
- KU Leuven, Laboratory of Molecular and Cellular Signalling, Department of Cellular and Molecular Medicine, Leuven, Belgium.
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Klar J, Hisatsune C, Baig SM, Tariq M, Johansson ACV, Rasool M, Malik NA, Ameur A, Sugiura K, Feuk L, Mikoshiba K, Dahl N. Abolished InsP3R2 function inhibits sweat secretion in both humans and mice. J Clin Invest 2014; 124:4773-80. [PMID: 25329695 DOI: 10.1172/jci70720] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2013] [Accepted: 09/11/2014] [Indexed: 12/12/2022] Open
Abstract
There are 3 major sweat-producing glands present in skin; eccrine, apocrine, and apoeccrine glands. Due to the high rate of secretion, eccrine sweating is a vital regulator of body temperature in response to thermal stress in humans; therefore, an inability to sweat (anhidrosis) results in heat intolerance that may cause impaired consciousness and death. Here, we have reported 5 members of a consanguineous family with generalized, isolated anhidrosis, but morphologically normal eccrine sweat glands. Whole-genome analysis identified the presence of a homozygous missense mutation in ITPR2, which encodes the type 2 inositol 1,4,5-trisphosphate receptor (InsP3R2), that was present in all affected family members. We determined that the mutation is localized within the pore forming region of InsP3R2 and abrogates Ca2+ release from the endoplasmic reticulum, which suggests that intracellular Ca2+ release by InsP3R2 in clear cells of the sweat glands is important for eccrine sweat production. Itpr2-/- mice exhibited a marked reduction in sweat secretion, and evaluation of sweat glands from Itpr2-/- animals revealed a decrease in Ca2+ response compared with controls. Together, our data indicate that loss of InsP3R2-mediated Ca2+ release causes isolated anhidrosis in humans and suggest that specific InsP3R inhibitors have the potential to reduce sweat production in hyperhidrosis.
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Wagner LE, Groom LA, Dirksen RT, Yule DI. Characterization of ryanodine receptor type 1 single channel activity using "on-nucleus" patch clamp. Cell Calcium 2014; 56:96-107. [PMID: 24972488 DOI: 10.1016/j.ceca.2014.05.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Revised: 05/27/2014] [Accepted: 05/28/2014] [Indexed: 12/13/2022]
Abstract
In this study, we provide the first description of the biophysical and pharmacological properties of ryanodine receptor type 1 (RyR1) expressed in a native membrane using the on-nucleus configuration of the patch clamp technique. A stable cell line expressing rabbit RyR1 was established (HEK-RyR1) using the FLP-in 293 cell system. In contrast to untransfected cells, RyR1 expression was readily demonstrated by immunoblotting and immunocytochemistry in HEK-RyR1 cells. In addition, the RyR1 agonists 4-CMC and caffeine activated Ca(2+) release that was inhibited by high concentrations of ryanodine. On nucleus patch clamp was performed in nuclei prepared from HEK-RyR1 cells. Raising the [Ca(2+)] in the patch pipette resulted in the appearance of a large conductance cation channel with well resolved kinetics and the absence of prominent subconductance states. Current versus voltage relationships were ohmic and revealed a chord conductance of ∼750pS or 450pS in symmetrical 250mM KCl or CsCl, respectively. The channel activity was markedly enhanced by caffeine and exposure to ryanodine resulted in the appearance of a subconductance state with a conductance ∼40% of the full channel opening with a Po near unity. In total, these properties are entirely consistent with RyR1 channel activity. Exposure of RyR1 channels to cyclic ADP ribose (cADPr), nicotinic acid adenine dinucleotide phosphate (NAADP) or dantrolene did not alter the single channel activity stimulated by Ca(2+), and thus, it is unlikely these molecules directly modulate RyR1 channel activity. In summary, we describe an experimental platform to monitor the single channel properties of RyR channels. We envision that this system will be influential in characterizing disease-associated RyR mutations and the molecular determinants of RyR channel modulation.
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Affiliation(s)
- Larry E Wagner
- Department of Pharmacology and Physiology, University of Rochester, 601 Elmwood Ave, Rochester, NY 14642, United States
| | - Linda A Groom
- Department of Pharmacology and Physiology, University of Rochester, 601 Elmwood Ave, Rochester, NY 14642, United States
| | - Robert T Dirksen
- Department of Pharmacology and Physiology, University of Rochester, 601 Elmwood Ave, Rochester, NY 14642, United States
| | - David I Yule
- Department of Pharmacology and Physiology, University of Rochester, 601 Elmwood Ave, Rochester, NY 14642, United States.
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Ivanova H, Vervliet T, Missiaen L, Parys JB, De Smedt H, Bultynck G. Inositol 1,4,5-trisphosphate receptor-isoform diversity in cell death and survival. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2014; 1843:2164-83. [PMID: 24642269 DOI: 10.1016/j.bbamcr.2014.03.007] [Citation(s) in RCA: 142] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Revised: 03/06/2014] [Accepted: 03/09/2014] [Indexed: 01/22/2023]
Abstract
Cell-death and -survival decisions are critically controlled by intracellular Ca(2+) homeostasis and dynamics at the level of the endoplasmic reticulum (ER). Inositol 1,4,5-trisphosphate (IP3) receptors (IP3Rs) play a pivotal role in these processes by mediating Ca(2+) flux from the ER into the cytosol and mitochondria. Hence, it is clear that many pro-survival and pro-death signaling pathways and proteins affect Ca(2+) signaling by directly targeting IP3R channels, which can happen in an IP3R-isoform-dependent manner. In this review, we will focus on how the different IP3R isoforms (IP3R1, IP3R2 and IP3R3) control cell death and survival. First, we will present an overview of the isoform-specific regulation of IP3Rs by cellular factors like IP3, Ca(2+), Ca(2+)-binding proteins, adenosine triphosphate (ATP), thiol modification, phosphorylation and interacting proteins, and of IP3R-isoform specific expression patterns. Second, we will discuss the role of the ER as a Ca(2+) store in cell death and survival and how IP3Rs and pro-survival/pro-death proteins can modulate the basal ER Ca(2+) leak. Third, we will review the regulation of the Ca(2+)-flux properties of the IP3R isoforms by the ER-resident and by the cytoplasmic proteins involved in cell death and survival as well as by redox regulation. Hence, we aim to highlight the specific roles of the various IP3R isoforms in cell-death and -survival signaling. This article is part of a Special Issue entitled: Calcium signaling in health and disease. Guest Editors: Geert Bultynck, Jacques Haiech, Claus W. Heizmann, Joachim Krebs, and Marc Moreau.
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Affiliation(s)
- Hristina Ivanova
- KU Leuven Lab. of Molecular and Cellular Signaling, Dept. of Cellular and Molecular Medicine, Campus Gasthuisberg O&N I Box 802, Herestraat 49, BE-3000 Leuven, Belgium
| | - Tim Vervliet
- KU Leuven Lab. of Molecular and Cellular Signaling, Dept. of Cellular and Molecular Medicine, Campus Gasthuisberg O&N I Box 802, Herestraat 49, BE-3000 Leuven, Belgium
| | - Ludwig Missiaen
- KU Leuven Lab. of Molecular and Cellular Signaling, Dept. of Cellular and Molecular Medicine, Campus Gasthuisberg O&N I Box 802, Herestraat 49, BE-3000 Leuven, Belgium
| | - Jan B Parys
- KU Leuven Lab. of Molecular and Cellular Signaling, Dept. of Cellular and Molecular Medicine, Campus Gasthuisberg O&N I Box 802, Herestraat 49, BE-3000 Leuven, Belgium
| | - Humbert De Smedt
- KU Leuven Lab. of Molecular and Cellular Signaling, Dept. of Cellular and Molecular Medicine, Campus Gasthuisberg O&N I Box 802, Herestraat 49, BE-3000 Leuven, Belgium.
| | - Geert Bultynck
- KU Leuven Lab. of Molecular and Cellular Signaling, Dept. of Cellular and Molecular Medicine, Campus Gasthuisberg O&N I Box 802, Herestraat 49, BE-3000 Leuven, Belgium.
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cAMP and Ca²⁺ signaling in secretory epithelia: crosstalk and synergism. Cell Calcium 2014; 55:385-93. [PMID: 24613710 DOI: 10.1016/j.ceca.2014.01.006] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2013] [Revised: 01/29/2014] [Accepted: 01/30/2014] [Indexed: 12/15/2022]
Abstract
The Ca(2+) and cAMP/PKA pathways are the primary signaling systems in secretory epithelia that control virtually all secretory gland functions. Interaction and crosstalk in Ca(2+) and cAMP signaling occur at multiple levels to control and tune the activity of each other. Physiologically, Ca(2+) and cAMP signaling operate at 5-10% of maximal strength, but synergize to generate the maximal response. Although synergistic action of the Ca(2+) and cAMP signaling is the common mode of signaling and has been known for many years, we know very little of the molecular mechanism and mediators of the synergism. In this review, we discuss crosstalk between the Ca(2+) and cAMP signaling and the function of IRBIT (IP3 receptors binding protein release with IP3) as a third messenger that mediates the synergistic action of the Ca(2+) and cAMP signaling.
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Hong JH, Park S, Shcheynikov N, Muallem S. Mechanism and synergism in epithelial fluid and electrolyte secretion. Pflugers Arch 2013; 466:1487-99. [PMID: 24240699 DOI: 10.1007/s00424-013-1390-1] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Revised: 10/16/2013] [Accepted: 10/17/2013] [Indexed: 01/04/2023]
Abstract
A central function of epithelia is the control of the volume and electrolyte composition of bodily fluids through vectorial transport of electrolytes and the obligatory H2O. In exocrine glands, fluid and electrolyte secretion is carried out by both acinar and duct cells, with the portion of fluid secreted by each cell type varying among glands. All acinar cells secrete isotonic, plasma-like fluid, while the duct determines the final electrolyte composition of the fluid by absorbing most of the Cl(-) and secreting HCO3 (-). The key transporters mediating acinar fluid and electrolyte secretion are the basolateral Na(+)/K(+) /2Cl(-) cotransporter, the luminal Ca(2+)-activated Cl(-) channel ANO1 and basolateral and luminal Ca(2+)-activated K(+) channels. Ductal fluid and HCO3 (-) secretion are mediated by the basolateral membrane Na(+)-HCO3 (-) cotransporter NBCe1-B and the luminal membrane Cl(-)/HCO3 (-) exchanger slc26a6 and the Cl(-) channel CFTR. The function of the transporters is regulated by multiple inputs, which in the duct include major regulation by the WNK/SPAK pathway that inhibit secretion and the IRBIT/PP1 pathway that antagonize the effects of the WNK/SPAK pathway to both stimulate and coordinate the secretion. The function of these regulatory pathways in secretory glands acinar cells is yet to be examined. An important concept in biology is synergism among signaling pathways to generate the final physiological response that ensures regulation with high fidelity and guards against cell toxicity. While synergism is observed in all epithelial functions, the molecular mechanism mediating the synergism is not known. Recent work reveals a central role for IRBIT as a third messenger that integrates and synergizes the function of the Ca(2+) and cAMP signaling pathways in activation of epithelial fluid and electrolyte secretion. These concepts are discussed in this review using secretion by the pancreatic and salivary gland ducts as model systems.
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Affiliation(s)
- Jeong Hee Hong
- Epithelial Signaling and Transport Section, Molecular Physiology and Therapeutics Branch, National Institute of Dental and Craniofacial Research, National Institute of Health, Bethesda, MD, 20892, USA
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Park S, Shcheynikov N, Hong JH, Zheng C, Suh SH, Kawaai K, Ando H, Mizutani A, Abe T, Kiyonari H, Seki G, Yule D, Mikoshiba K, Muallem S. Irbit mediates synergy between ca(2+) and cAMP signaling pathways during epithelial transport in mice. Gastroenterology 2013; 145:232-241. [PMID: 23542070 PMCID: PMC3696401 DOI: 10.1053/j.gastro.2013.03.047] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2013] [Revised: 03/20/2013] [Accepted: 03/22/2013] [Indexed: 12/17/2022]
Abstract
BACKGROUND & AIMS The cyclic adenosine monophosphate (cAMP) and Ca(2+) signaling pathways synergize to regulate many physiological functions. However, little is known about the mechanisms by which these pathways interact. We investigated the synergy between these signaling pathways in mouse pancreatic and salivary gland ducts. METHODS We created mice with disruptions in genes encoding the solute carrier family 26, member 6 (Slc26a6(-/-) mice) and inositol 1,4,5-triphosphate (InsP3) receptor-binding protein released with InsP3 (Irbit(-/-)) mice. We investigated fluid secretion by sealed pancreatic ducts and the function of Slc26a6 and the cystic fibrosis transmembrane conductance regulator (CFTR) in HeLa cells and in ducts isolated from mouse pancreatic and salivary glands. Slc26a6 activity was assayed by measuring intracellular pH, and CFTR activity was assayed by measuring Cl(-) current. Protein interactions were determined by immunoprecipitation analyses. RESULTS Irbit mediated the synergistic activation of CFTR and Slc26a6 by Ca(2+) and cAMP. In resting cells, Irbit was sequestered by InsP3 receptors (IP3Rs) in the endoplasmic reticulum. Stimulation of Gs-coupled receptors led to phosphorylation of IP3Rs, which increased their affinity for InsP3 and reduced their affinity for Irbit. Subsequent weak stimulation of Gq-coupled receptors, which led to production of low levels of IP3, caused dissociation of Irbit from IP3Rs and allowed translocation of Irbit to CFTR and Slc26a6 in the plasma membrane. These processes stimulated epithelial secretion of electrolytes and fluid. These pathways were not observed in pancreatic and salivary glands from Irbit(-/-) or Slc26a6(-/-) mice, or in salivary gland ducts expressing mutant forms of IP3Rs that could not undergo protein kinase A-mediated phosphorylation. CONCLUSIONS Irbit promotes synergy between the Ca(2+) and cAMP signaling pathways in cultured cells and in pancreatic and salivary ducts from mice. Defects in this pathway could be involved in cystic fibrosis, pancreatitis, or Sjögren syndrome.
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Affiliation(s)
- Seonghee Park
- Epithelial Signaling and Transport Section, Molecular Physiology and Therapeutics Branch, National Institute of Dental and Craniofacial Research, National Institute of Health, Bethesda MD, 20892,Department of Physiology, School of Medicine, Ewha Womans University, 911-1 Mok-6-dong, Yang Chun-gu, Seoul 158-710, Republic of Korea
| | - Nikolay Shcheynikov
- Epithelial Signaling and Transport Section, Molecular Physiology and Therapeutics Branch, National Institute of Dental and Craniofacial Research, National Institute of Health, Bethesda MD, 20892
| | - Jeong Hee Hong
- Epithelial Signaling and Transport Section, Molecular Physiology and Therapeutics Branch, National Institute of Dental and Craniofacial Research, National Institute of Health, Bethesda MD, 20892
| | - Changyu Zheng
- Epithelial Signaling and Transport Section, Molecular Physiology and Therapeutics Branch, National Institute of Dental and Craniofacial Research, National Institute of Health, Bethesda MD, 20892
| | - Suk Hyo Suh
- Department of Physiology, School of Medicine, Ewha Womans University, 911-1 Mok-6-dong, Yang Chun-gu, Seoul 158-710, Republic of Korea
| | - Katsuhiro Kawaai
- Laboratory for Developmental Neurobiology, Brain Science Institute, Institute of Physical and Chemical Research (RIKEN), 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Hideaki Ando
- Laboratory for Developmental Neurobiology, Brain Science Institute, Institute of Physical and Chemical Research (RIKEN), 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Akihiro Mizutani
- Department of Pharmacotherapeutics, Showa Pharmaceutical University, 3-3165 Higashi-tamagawagakuen, Machida, Tokyo 194-8543
| | - Takaya Abe
- Laboratory for Animal Resources and Genetic Engineering, RIKEN Center for Developmental Biology, 2-2-3 Minatojima Minami, Chuou-ku, Kobe 650-0047
| | - Hiroshi Kiyonari
- Laboratory for Animal Resources and Genetic Engineering, RIKEN Center for Developmental Biology, 2-2-3 Minatojima Minami, Chuou-ku, Kobe 650-0047
| | - George Seki
- Department of Internal Medicine, Faculty of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8635, Japan
| | - David Yule
- Department of Pharmacology & Physiology, School of Medicine and Dentistry, University of Rochester Medical Center, Rochester, NY, USA
| | - Katsuhiko Mikoshiba
- Laboratory for Developmental Neurobiology, Brain Science Institute, Institute of Physical and Chemical Research (RIKEN), 2-1 Hirosawa, Wako, Saitama 351-0198, Japan,Address for correspondence: or
| | - Shmuel Muallem
- Epithelial Signaling and Transport Section, Molecular Physiology and Therapeutics Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, Maryland.
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Ida Y, Kidera A. The conserved Arg241-Glu439 salt bridge determines flexibility of the inositol 1,4,5-trisphosphate receptor binding core in the ligand-free state. Proteins 2013; 81:1699-708. [PMID: 23606071 DOI: 10.1002/prot.24304] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2013] [Revised: 03/15/2013] [Accepted: 03/26/2013] [Indexed: 12/13/2022]
Abstract
Inositol 1,4,5-trisphosphate receptor (InsP3 R) is an intracellular Ca(2+) -release channel activated by binding of inositol 1,4,5-trisphosphate (InsP3 ) to the InsP3 binding core (IBC). Structural change in the IBC upon InsP3 binding is the key process in channel pore opening. In this study, we performed molecular dynamics (MD) simulations of the InsP3 -free form of the IBC, starting with removal of InsP3 from the InsP3 -bound crystal structure, and obtained the structural ensemble of the InsP3 -free form of the IBC. The simulation revealed that the two domains of the IBC largely fluctuate around the average structure with the hinge angle opened 17° more than in the InsP3 -bound form, and the twist angle rotated by 45°, forming interdomain contacts that are different from those in the bound form. The InsP3 binding loop was disordered. The InsP3 -free form thus obtained was reproduced four times in simulations started from a fully extended configuration of the two domains. Simulations beginning with the fully extended form indicated that formation of a salt bridge between Arg241 and Glu439 is crucial for stabilizing the closed form of the two domains. Mutation of Arg241 to Gln prevented formation of the compact structure by the two domains, but the fully flexible domain arrangement was maintained. Thus, the Arg241-Glu439 salt bridge determines the flexibility of the InsP3 -free form of the IBC.
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Affiliation(s)
- Yoichi Ida
- Department of Supramolecular Biology, Graduate School of Nanobioscience, Yokohama City University, Yokohama, 230-0045, Japan
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Alzayady KJ, Chandrasekhar R, Yule DI. Fragmented inositol 1,4,5-trisphosphate receptors retain tetrameric architecture and form functional Ca2+ release channels. J Biol Chem 2013; 288:11122-34. [PMID: 23479737 DOI: 10.1074/jbc.m113.453241] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Inositol 1,4,5-trisphosphate receptor isoforms are a family of ubiquitously expressed ligand-gated channels encoded by three individual genes. The proteins are localized to membranes of intracellular Ca(2+) stores and play pivotal roles in Ca(2+) homeostasis. Previous studies have demonstrated that IP3R1 is cleaved by the intracellular proteases calpain and caspase both in vivo and in vitro. However, the resultant cleavage products are poorly defined, and the functional consequences of these proteolytic events are not fully understood. We demonstrate that IP3R1 is cleaved during staurosporine-induced apoptosis, yielding N-terminal fragments encompassing the ligand-binding domain and the majority of the central modulatory domain together with a C-terminal fragment containing the channel domain and cytosolic tail. Notably, these fragments remain associated with the membrane after initiation of apoptotic cleavage. Furthermore, when recombinant IP3R1 fragments, corresponding to those predicted to be generated by caspase or calpain cleavage, are stably coexpressed in cells, they physically associate and form functional channels. These data provide novel insights regarding the regulation of IP3R1 during proteolysis and provide direct evidence that polypeptide continuity is not required for IP3R activation and Ca(2+) release.
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Affiliation(s)
- Kamil J Alzayady
- Department of Pharmacology and Physiology, University of Rochester, Rochester, New York 14642, USA
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Lee D, Michalak M. Calcium and bioenergetics: from endoplasmic reticulum to mitochondria. Anim Cells Syst (Seoul) 2012. [DOI: 10.1080/19768354.2012.685181] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
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