1
|
Nakahari T, Suzuki C, Kawaguchi K, Hosogi S, Tanaka S, Asano S, Inui T, Marunaka Y. Ambroxol-Enhanced Frequency and Amplitude of Beating Cilia Controlled by a Voltage-Gated Ca 2+ Channel, Cav1.2, via pH i Increase and [Cl -] i Decrease in the Lung Airway Epithelial Cells of Mice. Int J Mol Sci 2023; 24:16976. [PMID: 38069298 PMCID: PMC10707002 DOI: 10.3390/ijms242316976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Revised: 11/25/2023] [Accepted: 11/28/2023] [Indexed: 12/18/2023] Open
Abstract
Ambroxol (ABX), a frequently prescribed secretolytic agent which enhances the ciliary beat frequency (CBF) and ciliary bend angle (CBA, an index of amplitude) by 30%, activates a voltage-dependent Ca2+ channel (CaV1.2) and a small transient Ca2+ release in the ciliated lung airway epithelial cells (c-LAECs) of mice. The activation of CaV1.2 alone enhanced the CBF and CBA by 20%, mediated by a pHi increasei and a [Cl-]i decrease in the c-LAECs. The increase in pHi, which was induced by the activation of the Na+-HCO3- cotransporter (NBC), enhanced the CBF (by 30%) and CBA (by 15-20%), and a decrease in [Cl-]i, which was induced by the Cl- release via anoctamine 1 (ANO1), enhanced the CBA (by 10-15%). While a Ca2+-free solution or nifedipine (an inhibitor of CaV1.2) inhibited 70% of the CBF and CBA enhancement using ABX, CaV1.2 enhanced most of the CBF and CBA increases using ABX. The activation of the CaV1.2 existing in the cilia stimulates the NBC to increase pHi and ANO1 to decrease the [Cl-]i in the c-LAECs. In conclusion, the pHi increase and the [Cl-]i decrease enhanced the CBF and CBA in the ABX-stimulated c-LAECs.
Collapse
Affiliation(s)
- Takashi Nakahari
- Research Unit for Epithelial Physiology, Research Organization of Science and Technology, BKC, Ritsumeikan University, Kusatsu 525-8577, Japan;
- Medical Research Institute, Kyoto Industrial Health Association, Kyoto 604-8472, Japan
| | - Chihiro Suzuki
- Laboratory of Pharmacotherapy, Faculty of Pharmacy, Osaka Medical and Pharmaceutical University, Takatsuki 569-1094, Japan; (C.S.); (S.T.)
| | - Kotoku Kawaguchi
- Department of Molecular Physiology, Faculty of Pharmacy, BKC, Ritsumeikan University, Kusatsu 525-8577, Japan; (K.K.); (S.A.)
| | - Shigekuni Hosogi
- Department of Clinical and Translational Physiology, Kyoto Pharmaceutical University, Kyoto 607-8414, Japan;
| | - Saori Tanaka
- Laboratory of Pharmacotherapy, Faculty of Pharmacy, Osaka Medical and Pharmaceutical University, Takatsuki 569-1094, Japan; (C.S.); (S.T.)
| | - Shinji Asano
- Department of Molecular Physiology, Faculty of Pharmacy, BKC, Ritsumeikan University, Kusatsu 525-8577, Japan; (K.K.); (S.A.)
| | - Toshio Inui
- Saisei Mirai Clinics, Moriguchi 570-0012, Japan;
| | - Yoshinori Marunaka
- Research Unit for Epithelial Physiology, Research Organization of Science and Technology, BKC, Ritsumeikan University, Kusatsu 525-8577, Japan;
- Medical Research Institute, Kyoto Industrial Health Association, Kyoto 604-8472, Japan
| |
Collapse
|
2
|
Li H, Korcari A, Ciufo D, Mendias CL, Rodeo SA, Buckley MR, Loiselle AE, Pitt GS, Cao C. Increased Ca 2+ signaling through Ca V 1.2 induces tendon hypertrophy with increased collagen fibrillogenesis and biomechanical properties. FASEB J 2023; 37:e23007. [PMID: 37261735 DOI: 10.1096/fj.202300607r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 05/03/2023] [Accepted: 05/17/2023] [Indexed: 06/02/2023]
Abstract
Tendons are tension-bearing tissues transmitting force from muscle to bone for body movement. This mechanical loading is essential for tendon development, homeostasis, and healing after injury. While Ca2+ signaling has been studied extensively for its roles in mechanotransduction, regulating muscle, bone, and cartilage development and homeostasis, knowledge about Ca2+ signaling and the source of Ca2+ signals in tendon fibroblast biology are largely unknown. Here, we investigated the function of Ca2+ signaling through CaV 1.2 voltage-gated Ca2+ channel in tendon formation. Using a reporter mouse, we found that CaV 1.2 is highly expressed in tendon during development and downregulated in adult homeostasis. To assess its function, we generated ScxCre;CaV 1.2TS mice that express a gain-of-function mutant CaV 1.2 in tendon. We found that mutant tendons were hypertrophic, with more tendon fibroblasts but decreased cell density. TEM analyses demonstrated increased collagen fibrillogenesis in the hypertrophic tendons. Biomechanical testing revealed that the hypertrophic tendons display higher peak load and stiffness, with no changes in peak stress and elastic modulus. Proteomic analysis showed no significant difference in the abundance of type I and III collagens, but mutant tendons had about two-fold increase in other ECM proteins such as tenascin C, tenomodulin, periostin, type XIV and type VIII collagens, around 11-fold increase in the growth factor myostatin, and significant elevation of matrix remodeling proteins including Mmp14, Mmp2, and cathepsin K. Taken together, these data highlight roles for increased Ca2+ signaling through CaV 1.2 on regulating expression of myostatin growth factor and ECM proteins for tendon collagen fibrillogenesis during tendon formation.
Collapse
Affiliation(s)
- Haiyin Li
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, New York, USA
- Department of Orthopeadics, University of Rochester Medical Center, Rochester, New York, USA
| | - Antonion Korcari
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, New York, USA
- Department of Biomedical Engineering, University of Rochester Medical Center, Rochester, New York, USA
| | - David Ciufo
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, New York, USA
- Department of Orthopeadics, University of Rochester Medical Center, Rochester, New York, USA
| | | | - Scott A Rodeo
- Sports Medicine and Shoulder Service, Hospital for Special Surgery, New York, New York, USA
| | - Mark R Buckley
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, New York, USA
- Department of Biomedical Engineering, University of Rochester Medical Center, Rochester, New York, USA
| | - Alayna E Loiselle
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, New York, USA
- Department of Orthopeadics, University of Rochester Medical Center, Rochester, New York, USA
| | - Geoffrey S Pitt
- Cardiovascular Research Institute, Weill Cornell Medicine, New York, New York, USA
| | - Chike Cao
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, New York, USA
- Department of Orthopeadics, University of Rochester Medical Center, Rochester, New York, USA
| |
Collapse
|
3
|
Čonkaš J, Sabol M, Ozretić P. 'Toxic Masculinity': What Is Known about the Role of Androgen Receptors in Head and Neck Squamous Cell Carcinoma. Int J Mol Sci 2023; 24:ijms24043766. [PMID: 36835177 PMCID: PMC9965076 DOI: 10.3390/ijms24043766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 02/03/2023] [Accepted: 02/09/2023] [Indexed: 02/16/2023] Open
Abstract
Head and neck squamous cell carcinoma (HNSCC), the most prevalent cancer in the head and neck region, develops from the mucosal epithelium of the upper aerodigestive tract. Its development directly correlates with alcohol and/or tobacco consumption and infection with human papillomavirus. Interestingly, the relative risk for HNSCC is up to five times higher in males, so it is considered that the endocrine microenvironment is another risk factor. A gender-specific risk for HNSCC suggests either the existence of specific risk factors that affect only males or that females have defensive hormonal and metabolic features. In this review, we summarized the current knowledge about the role of both nuclear and membrane androgen receptors (nAR and mARs, respectively) in HNSCC. As expected, the significance of nAR is much better known; it was shown that increased nAR expression was observed in HNSCC, while treatment with dihydrotestosterone increased proliferation, migration, and invasion of HNSCC cells. For only three out of five currently known mARs-TRPM8, CaV1.2, and OXER1-it was shown either their increased expression in various types of HNSCC or that their increased activity enhanced the migration and invasion of HNSCC cells. The primary treatments for HNSCC are surgery and radiotherapy, but targeted immunotherapies are on the rise. On the other hand, given the evidence of elevated nAR expression in HNSCC, this receptor represents a potential target for antiandrogen therapy. Moreover, there is still plenty of room for further examination of mARs' role in HNSCC diagnosis, prognosis, and treatment.
Collapse
|
4
|
Qi JY, Kang DY, Yu J, Zhang MZ. Suxiao Jiuxin Pills Prevent Ventricular Fibrillation from Inhibiting L-type Calcium Currents CaV1.2 in vivo and in vitro. Chin J Integr Med 2023; 29:108-118. [PMID: 36327050 DOI: 10.1007/s11655-022-3623-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/11/2022] [Indexed: 11/06/2022]
Abstract
OBJECTIVE To investigate whether Suxiao Jiuxin Pills (SJP), a Chinese herbal remedy, is an anti-ventricular fibrillation (VF) agent. METHODS VF was induced by isoproterenolol (ISO) intraperitoneal injection followed by electrical pacing in mice and rabbits. The effects of SJP on the L-type calcium channel current (CaV1.2), voltage-dependent sodium channel current (INa), rapid and slow delayed rectifier potassium channel current (IKr and IKs, respectively) were studied by whole-cell patch-clamp method. Computer simulation was implemented to incorporate the experimental data of SJP effects on the CaV1.2 current into the action potential (AP) and pseudo-electrocardiography (pseudo-ECG) models. RESULTS SJP prevented VF induction and reduced VF durations significantly in mice and rabbits. Patch-clamp experiments revealed that SJP decreased the peak amplitude of the CaV1.2 current with a half maximal concentration (IC50) value of 16.9 mg/L (SJP-30 mg/L, -32.8 ± 6.1 pA; Verapamil, -16.2 ±1.8 pA; vs. control, -234.5 ±16.7 pA, P<0.01, respectively). The steady-state activation curve, inactivation curve, and the recovery from inactivation of the CaV1.2 current were not shifted significantly. Specifically, SJP did not altered INa, IKr, and IKs currents significantly (SJP vs. control, P>0.05). Computer simulation showed that SJP-reduced CaV1.2 current shortened the AP duration, transiting VF into sinus rhythm in pseudo-ECG. CONCLUSION SJP reduced VF via inhibiting the CaV1.2 current with in vivo, in vitro, and in silico studies, which provide experimental basis for SJP anti-VF clinical application.
Collapse
Affiliation(s)
- Jian-Yong Qi
- Acute Myocardial Infarction Key Laboratory of Chinese Medicine in Guangzhou, the 2nd Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangdong Province Hospital of Chinese Medicine, Guangzhou, 510006, China.,Intensive Care Research Team of Traditional Chinese Medicine, the 2nd Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangdong Province Hospital of Chinese Medicine, Guangzhou, 510006, China
| | - Dong-Yuan Kang
- Acute Myocardial Infarction Key Laboratory of Chinese Medicine in Guangzhou, the 2nd Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangdong Province Hospital of Chinese Medicine, Guangzhou, 510006, China.,Intensive Care Research Team of Traditional Chinese Medicine, the 2nd Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangdong Province Hospital of Chinese Medicine, Guangzhou, 510006, China
| | - Juan Yu
- Animal Center, the 2nd Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangdong Province Hospital of Chinese Medicine, Guangdong Province Academy of Chinese Medicine, Guangzhou, 510006, China
| | - Min-Zhou Zhang
- Acute Myocardial Infarction Key Laboratory of Chinese Medicine in Guangzhou, the 2nd Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangdong Province Hospital of Chinese Medicine, Guangzhou, 510006, China. .,Intensive Care Research Team of Traditional Chinese Medicine, the 2nd Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangdong Province Hospital of Chinese Medicine, Guangzhou, 510006, China.
| |
Collapse
|
5
|
Davis MJ, Kim HJ, Li M, Zawieja SD. A vascular smooth muscle-specific integrin-α8 Cre mouse for lymphatic contraction studies that allows male-female comparisons and avoids visceral myopathy. Front Physiol 2023; 13:1060146. [PMID: 36714313 PMCID: PMC9878285 DOI: 10.3389/fphys.2022.1060146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2022] [Accepted: 12/20/2022] [Indexed: 01/14/2023] Open
Abstract
Introduction: The widely-used, tamoxifen-inducible, smooth muscle (SM)-specific Cre, Myh11-CreERT2 , suffers from two disadvantages: 1) it is carried on the Y-chromosome and thus only effective for gene deletion in male mice, and 2) it recombines in both vascular and non-vascular SM, potentially leading to unwanted or confounding gastrointestinal phenotypes. Here, we tested the effectiveness of a new, SM-specific Cre, based on the integrin α8 promoter (Itga8-CreERT2 ), that has been recently developed and characterized, to assess the effects of Cav1.2 deletion on mouse lymphatic SM function. Methods: Cav1.2 (the L-type voltage-gated calcium channel) is essential for lymphatic pacemaking and contraction and its deletion using either Myh11-CreERT2 or Itga8-CreERT2 abolished spontaneous lymphatic contractions. Mouse lymphatic contractile function was assessed using two ex vivo methods. Results: Myh11-CreERT2 ; Cav1.2 f/f mice died of gastrointestinal obstruction within 20 days of the first tamoxifen injection, preceded by several days of progressively poor health, with symptoms including weight loss, poor grooming, hunched posture, and reduced overall activity. In contrast, Itga8-CreERT2 ; Cav1.2 f/f mice survived for >80 days after induction and were in normal health until the time of sacrifice for experimental studies. Cav1.2 deletion was equally effective in male and female mice. Discussion: Our results demonstrate that Itga8-CreER T2 can be used to effectively delete genes in lymphatic smooth muscle while avoiding potentially lethal visceral myopathy and allowing comparative studies of lymphatic contractile function in both male and female mice.
Collapse
Affiliation(s)
| | - Hae Jin Kim
- Department of Medical Pharmacology and Physiology, University of Missouri School of Medicine, Columbia, MO, United States
| | - Min Li
- Department of Medical Pharmacology and Physiology, University of Missouri School of Medicine, Columbia, MO, United States
| | - Scott D. Zawieja
- Department of Medical Pharmacology and Physiology, University of Missouri School of Medicine, Columbia, MO, United States
| |
Collapse
|
6
|
Abstract
The CACNA1C gene encodes the pore-forming subunit of the CaV1.2 L-type Ca2+ channel, a critical component of membrane physiology in multiple tissues, including the heart, brain, and immune system. As such, mutations altering the function of these channels have the potential to impact a wide array of cellular functions. The first mutations identified within CACNA1C were shown to cause a severe, multisystem disorder known as Timothy syndrome (TS), which is characterized by neurodevelopmental deficits, long-QT syndrome, life-threatening cardiac arrhythmias, craniofacial abnormalities, and immune deficits. Since this initial description, the number and variety of disease-associated mutations identified in CACNA1C have grown tremendously, expanding the range of phenotypes observed in affected patients. CACNA1C channelopathies are now known to encompass multisystem phenotypes as described in TS, as well as more selective phenotypes where patients may exhibit predominantly cardiac or neurological symptoms. Here, we review the impact of genetic mutations on CaV1.2 function and the resultant physiological consequences.
Collapse
Affiliation(s)
- Kevin G Herold
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - John W Hussey
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Ivy E Dick
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, USA.
| |
Collapse
|
7
|
Yadav DK, Anderson DE, Hell JW, Ames JB. Calmodulin promotes a Ca 2+ -dependent conformational change in the C-terminal regulatory domain of Ca V 1.2. FEBS Lett 2022; 596:2974-2985. [PMID: 36310389 PMCID: PMC9719739 DOI: 10.1002/1873-3468.14529] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Revised: 10/07/2022] [Accepted: 10/10/2022] [Indexed: 11/10/2023]
Abstract
Calmodulin (CaM) binds to the membrane-proximal cytosolic C-terminal domain of CaV 1.2 (residues 1520-1669, CT(1520-1669)) and causes Ca2+ -induced conformational changes that promote Ca2+ -dependent channel inactivation (CDI). We report biophysical studies that probe the structural interaction between CT(1520-1669) and CaM. The recombinantly expressed CT(1520-1669) is insoluble, but can be solubilized in the presence of Ca2+ -saturated CaM (Ca4 /CaM), but not in the presence of Ca2+ -free CaM (apoCaM). We show that half-calcified CaM (Ca2 /CaM12 ) forms a complex with CT(1520-1669) that is less soluble than CT(1520-1669) bound to Ca4 /CaM. The NMR spectrum of CT(1520-1669) reveals spectral differences caused by the binding of Ca2 /CaM12 versus Ca4 /CaM, suggesting that the binding of Ca2+ to the CaM N-lobe may induce a conformational change in CT(1520-1669).
Collapse
Affiliation(s)
| | - David E. Anderson
- Department of Chemistry, University of California, Davis, CA 95616, USA
| | - Johannes W. Hell
- Department of Pharmacology, University of California, Davis, CA 95616, USA
| | - James B. Ames
- Department of Chemistry, University of California, Davis, CA 95616, USA
| |
Collapse
|
8
|
Hovey L, Gamal El-Din TM, Catterall WA. Convergent regulation of Ca(V)1.2 channels by direct phosphorylation and by the small GTPase RAD in the cardiac fight-or-flight response. Proc Natl Acad Sci U S A 2022; 119:e2208533119. [PMID: 36215501 DOI: 10.1073/pnas.2208533119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The L-type calcium currents conducted by the cardiac CaV1.2 calcium channel initiate excitation-contraction coupling and serve as a key regulator of heart rate, rhythm, and force of contraction. CaV1.2 is regulated by β-adrenergic/protein kinase A (PKA)-mediated protein phosphorylation, proteolytic processing, and autoinhibition by its carboxyl-terminal domain (CT). The small guanosine triphosphatase (GTPase) RAD (Ras associated with diabetes) has emerged as a potent inhibitor of CaV1.2, and accumulating evidence suggests a key role for RAD in mediating β-adrenergic/PKA upregulation of channel activity. However, the relative roles of direct phosphorylation of CaV1.2 channels and phosphorylation of RAD in channel regulation remain uncertain. Here, we investigated the hypothesis that these two mechanisms converge to regulate CaV1.2 channels. Both RAD and the proteolytically processed distal CT (dCT) strongly reduced CaV1.2 activity. PKA phosphorylation of RAD and phosphorylation of Ser-1700 in the proximal CT (pCT) synergistically reversed this inhibition and increased CaV1.2 currents. Our findings reveal that the proteolytically processed form of CaV1.2 undergoes convergent regulation by direct phosphorylation of the CT and by phosphorylation of RAD. These parallel regulatory pathways provide a flexible mechanism for upregulation of the activity of CaV1.2 channels in the fight-or-flight response.
Collapse
|
9
|
Salveson I, Ames JB. Chemical shift assignments of the C-terminal domain of CaBP1 bound to the IQ-motif of voltage-gated Ca 2+ channel (Ca V1.2). Biomol NMR Assign 2022; 16:385-390. [PMID: 36064846 PMCID: PMC9510106 DOI: 10.1007/s12104-022-10108-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Accepted: 08/31/2022] [Indexed: 06/15/2023]
Abstract
The neuronal L-type voltage-gated Ca2+ channel (CaV1.2) interacts with Ca2+ binding protein 1 (CaBP1), that promotes Ca2+-induced channel activity. The binding of CaBP1 to the IQ-motif in CaV1.2 (residues 1644-1665) blocks the binding of calmodulin and prevents Ca2+-dependent inactivation of CaV1.2. This Ca2+-induced binding of CaBP1 to CaV1.2 is important for modulating neuronal synaptic plasticity, which may serve a role in learning and memory. Here we report NMR assignments of the C-terminal domain of CaBP1 (residues 99-167, called CaBP1C) that contains two Ca2+ bound at the third and fourth EF-hands (EF3 and EF4) and is bound to the CaV1.2 IQ-motif from CaV1.2 (BMRB accession no. 51518).
Collapse
Affiliation(s)
- Ian Salveson
- Department of Chemistry, University of California, Davis, Davis, CA, 95616, USA
| | - James B Ames
- Department of Chemistry, University of California, Davis, Davis, CA, 95616, USA.
| |
Collapse
|
10
|
Huang ZX, Qiu ZE, Chen L, Hou XC, Zhu YX, Zhou WL, Zhang YL. Cellular mechanism underlying the facilitation of contractile response induced by IL-25 in mouse tracheal smooth muscle. Am J Physiol Lung Cell Mol Physiol 2022; 323:L27-L36. [PMID: 35537103 DOI: 10.1152/ajplung.00468.2021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Asthma is a common heterogeneous respiratory disease characterized by airway inflammation and airway hyperresponsiveness (AHR) which is associated with abnormality in smooth muscle contractility. The epithelial cell-derived cytokine IL-25 is implicated in type 2 immune pathology including asthma, whereas the underlying mechanisms have not been fully elucidated. This study aims to investigate the effects of IL-25 on mouse tracheal smooth muscle contractility and elucidate the cellular mechanisms. Incubation with IL-25 augmented the contraction of mouse tracheal smooth muscles, which could be suppressed by the L-type voltage-dependent Ca2+ channel (L-VDCC) blocker nifedipine. Furthermore, IL-25 enhanced the cytosolic Ca2+ signals and triggered up-regulation of α1C L-VDCC (CaV1.2) in primary cultured mouse tracheal smooth muscle cells. Knocking down IL-17RA/IL-17RB receptors or inhibiting the transforming growth factor-β-activated kinase 1 (TAK1)-tumor progression locus 2 (TPL2)-MAPK kinase 1/2 (MEK1/2)-ERK1/2-activating protein-1 (AP-1) signaling pathways suppressed the IL-25-elicited up-regulation of CaV1.2 and hyperreactivity in tracheal smooth muscles. Moreover, inhibition of TPL2, ERK1/2 or L-VDCC alleviated the AHR symptom induced by IL-25 in a murine model. This study revealed that IL-25 potentiated the contraction of tracheal smooth muscle and evoked AHR via activation of TPL2-ERK1/2-CaV1.2 signaling, providing novel targets for the treatment of asthma with a high-IL-25 phenotype.
Collapse
Affiliation(s)
- Ze-Xin Huang
- School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Zhuo-Er Qiu
- School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Lei Chen
- School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Xiao-Chun Hou
- School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Yun-Xin Zhu
- School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Wen-Liang Zhou
- School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Yi-Lin Zhang
- School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| |
Collapse
|
11
|
Novelli V, Memmi M, Malovini A, Mazzanti A, Liu N, Yanfei R, Bongianino R, Denegri M, Monteforte N, Bloise R, Morini M, Napolitano C. The role of CACNA1C in Brugada syndrome: prevalence and phenotype of probands referred for genetic testing. Heart Rhythm 2022; 19:798-806. [PMID: 34999275 DOI: 10.1016/j.hrthm.2021.12.032] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 12/07/2021] [Accepted: 12/27/2021] [Indexed: 11/18/2022]
Abstract
BACKGROUND Contradictory evidence is available on the role of the CACNA1C gene, encoding for the α-subunit of the cardiac L-type calcium channel (CaV1.2), as a cause of the BrS3 variant of Brugada syndrome (BrS). OBJECTIVE We aimed at tackling this issue in a large BrS cohort to define the yield of molecular screening and to address the hypothesis if an appropriate patient selection could improve the clinical utility. METHODS A total of 709 patients entered this study. BrS probands (n= 563, consecutively referred) underwent CACNA1C sequencing. Two matched cohorts where defined: discovery cohort (n = 200 patients) and confirmation cohort (n = 363 patients). Furthermore, the clinical phenotypes of a matched SCN5A positive BrS cohort (n= 146) were included for comparative genotype-phenotype correlation. RESULTS In the discovery cohort, we identified 11 different rare variants in 9 patients of whom 10 (5%) were considered potentially causative based on their frequency in the general population. However, ACMG criteria were unable to classify the majority (80%) of them eventually labeled as variants of unknown significance (VUS). Functional studies revealed a loss of function for 9 variants pointing to a prevalence of CACNA1C causative variants in 4% in the discovery cohort. Genotype-phenotype correlation showed that pathogenic variants are significantly more frequent in patients with a shorter QTc (12.9 % vs 2.2 % in patients with QTc < 390 ms). CONCLUSION CACNA1C is an infrequent but definitive cause of BrS typically associated with short QT. Functional studies are highly relevant to improve variant interpretation.
Collapse
Affiliation(s)
- Valeria Novelli
- Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy; Istituto di Medicina Genomica, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Mirella Memmi
- Molecular Cardiology, Istituti Clinici Scientifici Maugeri, IRCCS, Pavia, Italy
| | - Alberto Malovini
- Laboratory of Informatics and Systems Engineering for Clinical Research, Istituti Clinici Scientifici Maugeri IRCCS, Pavia, Italy
| | - Andrea Mazzanti
- Molecular Cardiology, Istituti Clinici Scientifici Maugeri, IRCCS, Pavia, Italy; Department of Molecular Medicine, University of Pavia, Pavia, Italy
| | - Nian Liu
- Molecular Cardiology, Istituti Clinici Scientifici Maugeri, IRCCS, Pavia, Italy
| | - Ruan Yanfei
- Molecular Cardiology, Istituti Clinici Scientifici Maugeri, IRCCS, Pavia, Italy
| | - Rossana Bongianino
- Molecular Cardiology, Istituti Clinici Scientifici Maugeri, IRCCS, Pavia, Italy
| | - Marco Denegri
- Molecular Cardiology, Istituti Clinici Scientifici Maugeri, IRCCS, Pavia, Italy
| | - Nicola Monteforte
- Molecular Cardiology, Istituti Clinici Scientifici Maugeri, IRCCS, Pavia, Italy
| | - Raffaella Bloise
- Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy; Molecular Cardiology, Istituti Clinici Scientifici Maugeri, IRCCS, Pavia, Italy
| | - Massimo Morini
- Molecular Cardiology, Istituti Clinici Scientifici Maugeri, IRCCS, Pavia, Italy
| | - Carlo Napolitano
- Molecular Cardiology, Istituti Clinici Scientifici Maugeri, IRCCS, Pavia, Italy; Department of Molecular Medicine, University of Pavia, Pavia, Italy.
| |
Collapse
|
12
|
Abstract
L-type voltage-gated Ca2+ channels (CaV1.2 and CaV1.3, called CaV) interact with the Ca2+ sensor proteins, calmodulin (CaM) and Ca2+ binding Protein 1 (CaBP1), that oppositely control Ca2+-dependent channel activity. CaM and CaBP1 can each bind to the IQ-motif within the C-terminal cytosolic domain of CaV, which promotes increased channel open probability under basal conditions. At elevated cytosolic Ca2+ levels (caused by CaV channel opening), Ca2+-bound CaM binding to CaV is essential for promoting rapid Ca2+-dependent channel inactivation (CDI). By contrast, CaV binding to CaBP1 prevents CDI and promotes Ca2+-induced channel opening (called CDF). In this review, I provide an overview of the known structures of CaM and CaBP1 and their structural interactions with the IQ-motif to help understand how CaM promotes CDI, whereas CaBP1 prevents CDI and instead promotes CDF. Previous electrophysiology studies suggest that Ca2+-free forms of CaM and CaBP1 may pre-associate with CaV under basal conditions. However, previous Ca2+ binding data suggest that CaM and CaBP1 are both calculated to bind to Ca2+ with an apparent dissociation constant of ~100 nM when CaM or CaBP1 is bound to the IQ-motif. Since the neuronal basal cytosolic Ca2+ concentration is ~100 nM, nearly half of the neuronal CaV channels are suggested to be bound to Ca2+-bound forms of either CaM or CaBP1 under basal conditions. The pre-association of CaV with calcified forms of CaM or CaBP1 are predicted here to have functional implications. The Ca2+-bound form of CaBP1 is proposed to bind to CaV under basal conditions to block CaV binding to CaM, which could explain how CaBP1 might prevent CDI.
Collapse
Affiliation(s)
- James B Ames
- Department of Chemistry, University of California, Davis, CA 95616, USA
| |
Collapse
|
13
|
Endres D, Decher N, Röhr I, Vowinkel K, Domschke K, Komlosi K, Tzschach A, Gläser B, Schiele MA, Runge K, Süß P, Schuchardt F, Nickel K, Stallmeyer B, Rinné S, Schulze-Bahr E, Tebartz van Elst L. New Cav1.2 Channelopathy with High-Functioning Autism, Affective Disorder, Severe Dental Enamel Defects, a Short QT Interval, and a Novel CACNA1C Loss-Of-Function Mutation. Int J Mol Sci 2020; 21:ijms21228611. [PMID: 33203140 PMCID: PMC7696251 DOI: 10.3390/ijms21228611] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2020] [Revised: 11/04/2020] [Accepted: 11/07/2020] [Indexed: 12/12/2022] Open
Abstract
Complex neuropsychiatric-cardiac syndromes can be genetically determined. For the first time, the authors present a syndromal form of short QT syndrome in a 34-year-old German male patient with extracardiac features with predominant psychiatric manifestation, namely a severe form of secondary high-functioning autism spectrum disorder (ASD), along with affective and psychotic exacerbations, and severe dental enamel defects (with rapid wearing off his teeth) due to a heterozygous loss-of-function mutation in the CACNA1C gene (NM_000719.6: c.2399A > C; p.Lys800Thr). This mutation was found only once in control databases; the mutated lysine is located in the Cav1.2 calcium channel, is highly conserved during evolution, and is predicted to affect protein function by most pathogenicity prediction algorithms. L-type Cav1.2 calcium channels are widely expressed in the brain and heart. In the case presented, electrophysiological studies revealed a prominent reduction in the current amplitude without changes in the gating behavior of the Cav1.2 channel, most likely due to a trafficking defect. Due to the demonstrated loss of function, the p.Lys800Thr variant was finally classified as pathogenic (ACMG class 4 variant) and is likely to cause a newly described Cav1.2 channelopathy.
Collapse
Affiliation(s)
- Dominique Endres
- Section for Experimental Neuropsychiatry, Department of Psychiatry and Psychotherapy, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; (K.R.); (K.N.); (L.T.v.E.)
- Department of Psychiatry and Psychotherapy, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; (K.D.); (M.A.S.)
- Correspondence: ; Tel.: +49-761-270-66360
| | - Niels Decher
- Institute for Physiology and Pathophysiology, Vegetative Physiology and Marburg Center for Mind, Brain and Behavior-Philipps-University Marburg, 35037 Marburg, Germany; (N.D.); (I.R.); (K.V.); (S.R.)
| | - Isabell Röhr
- Institute for Physiology and Pathophysiology, Vegetative Physiology and Marburg Center for Mind, Brain and Behavior-Philipps-University Marburg, 35037 Marburg, Germany; (N.D.); (I.R.); (K.V.); (S.R.)
| | - Kirsty Vowinkel
- Institute for Physiology and Pathophysiology, Vegetative Physiology and Marburg Center for Mind, Brain and Behavior-Philipps-University Marburg, 35037 Marburg, Germany; (N.D.); (I.R.); (K.V.); (S.R.)
| | - Katharina Domschke
- Department of Psychiatry and Psychotherapy, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; (K.D.); (M.A.S.)
- Center for Basics in Neuromodulation, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
| | - Katalin Komlosi
- Institute of Human Genetics, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany; (K.K.); (A.T.); (B.G.)
| | - Andreas Tzschach
- Institute of Human Genetics, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany; (K.K.); (A.T.); (B.G.)
| | - Birgitta Gläser
- Institute of Human Genetics, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany; (K.K.); (A.T.); (B.G.)
| | - Miriam A. Schiele
- Department of Psychiatry and Psychotherapy, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; (K.D.); (M.A.S.)
| | - Kimon Runge
- Section for Experimental Neuropsychiatry, Department of Psychiatry and Psychotherapy, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; (K.R.); (K.N.); (L.T.v.E.)
- Department of Psychiatry and Psychotherapy, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; (K.D.); (M.A.S.)
| | - Patrick Süß
- Department of Molecular Neurology, University Hospital Erlangen, 91054 Erlangen, Germany;
| | - Florian Schuchardt
- Department of Neurology, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany;
| | - Kathrin Nickel
- Section for Experimental Neuropsychiatry, Department of Psychiatry and Psychotherapy, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; (K.R.); (K.N.); (L.T.v.E.)
- Department of Psychiatry and Psychotherapy, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; (K.D.); (M.A.S.)
| | - Birgit Stallmeyer
- Institute for Genetics of Heart Diseases, Department of Cardiovascular Medicine, University Hospital Münster, 48149 Münster, Germany; (B.S.); (E.S.-B.)
| | - Susanne Rinné
- Institute for Physiology and Pathophysiology, Vegetative Physiology and Marburg Center for Mind, Brain and Behavior-Philipps-University Marburg, 35037 Marburg, Germany; (N.D.); (I.R.); (K.V.); (S.R.)
| | - Eric Schulze-Bahr
- Institute for Genetics of Heart Diseases, Department of Cardiovascular Medicine, University Hospital Münster, 48149 Münster, Germany; (B.S.); (E.S.-B.)
| | - Ludger Tebartz van Elst
- Section for Experimental Neuropsychiatry, Department of Psychiatry and Psychotherapy, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; (K.R.); (K.N.); (L.T.v.E.)
- Department of Psychiatry and Psychotherapy, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; (K.D.); (M.A.S.)
| |
Collapse
|
14
|
Agus V, Janovjak H. All-Optical Miniaturized Co-culture Assay of Voltage-Gated Ca 2+ Channels. Methods Mol Biol 2020; 2173:247-260. [PMID: 32651923 DOI: 10.1007/978-1-0716-0755-8_17] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Light-activated proteins enable the reversible and spatiotemporal control of cellular events in optogenetics. Optogenetics is also rapidly expanding into the field of drug discovery where it provides cost-effective and noninvasive approaches for cell manipulation in high-throughput screens. Here, we present a prototypical cell-based assay that applies Channelrhodopsin2 (ChR2) to recapitulate physiological membrane potential changes and test for voltage-gated ion channel (VGIC) blockade. ChR2 and the voltage-gated Ca2+ channel 1.2 (CaV1.2) are expressed in individual HEK293 cell lines that are then co-cultured for formation of gap junctions and an electrical syncytium. This co-culture allows identification of blockers using parallel fluorescence plate readers in the 384-well plate format in an all-optical mode of operation. The assay is transferable to other VGICs by modularly combining new and existing cell lines and potentially also to other drug targets.
Collapse
Affiliation(s)
- Viviana Agus
- Department of Cell Biology, AXXAM S.p.A, Milan, Italy.
| | - Harald Janovjak
- Australian Regenerative Medicine Institute (ARMI), Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, VIC, Australia
- European Molecular Biology Laboratory Australia (EMBL Australia), Monash University, Clayton, VIC, Australia
| |
Collapse
|
15
|
Michels S, Dolga AM, Braun MD, Kisko TM, Sungur AÖ, Witt SH, Rietschel M, Dempfle A, Wöhr M, Schwarting RKW, Culmsee C. Interaction of the Psychiatric Risk Gene Cacna1c With Post-weaning Social Isolation or Environmental Enrichment Does Not Affect Brain Mitochondrial Bioenergetics in Rats. Front Cell Neurosci 2019; 13:483. [PMID: 31708752 PMCID: PMC6823196 DOI: 10.3389/fncel.2019.00483] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Accepted: 10/11/2019] [Indexed: 12/21/2022] Open
Abstract
The pathophysiology of neuropsychiatric disorders involves complex interactions between genetic and environmental risk factors. Confirmed by several genome-wide association studies, Cacna1c represents one of the most robustly replicated psychiatric risk genes. Besides genetic predispositions, environmental stress such as childhood maltreatment also contributes to enhanced disease vulnerability. Both, Cacna1c gene variants and stressful life events are associated with morphological alterations in the prefrontal cortex and the hippocampus. Emerging evidence suggests impaired mitochondrial bioenergetics as a possible underlying mechanism of these regional brain abnormalities. In the present study, we simulated the interaction of psychiatric disease-relevant genetic and environmental factors in rodents to investigate their potential effect on brain mitochondrial function using a constitutive heterozygous Cacna1c rat model in combination with a four-week exposure to either post-weaning social isolation, standard housing, or social and physical environmental enrichment. Mitochondria were isolated from the prefrontal cortex and the hippocampus to evaluate their bioenergetics, membrane potential, reactive oxygen species production, and respiratory chain complex protein levels. None of these parameters were considerably affected in this particular gene-environment setting. These negative results were very robust in all tested conditions demonstrating that Cacna1c depletion did not significantly translate into altered bioenergetic characteristics. Thus, further investigations are required to determine the disease-related effects on brain mitochondria.
Collapse
Affiliation(s)
- Susanne Michels
- Institute of Pharmacology and Clinical Pharmacy, University of Marburg, Marburg, Germany.,Center for Mind, Brain and Behavior, University of Marburg, Marburg, Germany
| | - Amalia M Dolga
- Department of Molecular Pharmacology, Faculty of Science and Engineering, Groningen Research Institute of Pharmacy (GRIP), University of Groningen, Groningen, Netherlands
| | - Moria D Braun
- Center for Mind, Brain and Behavior, University of Marburg, Marburg, Germany.,Department of Experimental and Biological Psychology, University of Marburg, Marburg, Germany
| | - Theresa M Kisko
- Center for Mind, Brain and Behavior, University of Marburg, Marburg, Germany.,Department of Experimental and Biological Psychology, University of Marburg, Marburg, Germany
| | - A Özge Sungur
- Center for Mind, Brain and Behavior, University of Marburg, Marburg, Germany.,Department of Experimental and Biological Psychology, University of Marburg, Marburg, Germany
| | - Stephanie H Witt
- Department of Genetic Epidemiology in Psychiatry, Central Institute of Mental Health, Mannheim, Germany
| | - Marcella Rietschel
- Department of Genetic Epidemiology in Psychiatry, Central Institute of Mental Health, Mannheim, Germany
| | - Astrid Dempfle
- Institute of Medical Informatics and Statistics, Kiel University, Kiel, Germany
| | - Markus Wöhr
- Center for Mind, Brain and Behavior, University of Marburg, Marburg, Germany.,Department of Experimental and Biological Psychology, University of Marburg, Marburg, Germany
| | - Rainer K W Schwarting
- Center for Mind, Brain and Behavior, University of Marburg, Marburg, Germany.,Department of Experimental and Biological Psychology, University of Marburg, Marburg, Germany
| | - Carsten Culmsee
- Institute of Pharmacology and Clinical Pharmacy, University of Marburg, Marburg, Germany.,Center for Mind, Brain and Behavior, University of Marburg, Marburg, Germany
| |
Collapse
|
16
|
Pitman KA, Ricci R, Gasperini R, Beasley S, Pavez M, Charlesworth J, Foa L, Young KM. The voltage-gated calcium channel CaV1.2 promotes adult oligodendrocyte progenitor cell survival in the mouse corpus callosum but not motor cortex. Glia 2019; 68:376-392. [PMID: 31605513 PMCID: PMC6916379 DOI: 10.1002/glia.23723] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Revised: 09/02/2019] [Accepted: 09/10/2019] [Indexed: 12/21/2022]
Abstract
Throughout life, oligodendrocyte progenitor cells (OPCs) proliferate and differentiate into myelinating oligodendrocytes. OPCs express cell surface receptors and channels that allow them to detect and respond to neuronal activity, including voltage‐gated calcium channel (VGCC)s. The major L‐type VGCC expressed by developmental OPCs, CaV1.2, regulates their differentiation. However, it is unclear whether CaV1.2 similarly influences OPC behavior in the healthy adult central nervous system (CNS). To examine the role of CaV1.2 in adulthood, we conditionally deleted this channel from OPCs by administering tamoxifen to P60 Cacna1cfl/fl (control) and Pdgfrα‐CreER:: Cacna1cfl/fl (CaV1.2‐deleted) mice. Whole cell patch clamp analysis revealed that CaV1.2 deletion reduced L‐type voltage‐gated calcium entry into adult OPCs by ~60%, confirming that it remains the major L‐type VGCC expressed by OPCs in adulthood. The conditional deletion of CaV1.2 from adult OPCs significantly increased their proliferation but did not affect the number of new oligodendrocytes produced or influence the length or number of internodes they elaborated. Unexpectedly, CaV1.2 deletion resulted in the dramatic loss of OPCs from the corpus callosum, such that 7 days after tamoxifen administration CaV1.2‐deleted mice had an OPC density ~42% that of control mice. OPC density recovered within 2 weeks of CaV1.2 deletion, as the lost OPCs were replaced by surviving CaV1.2‐deleted OPCs. As OPC density was not affected in the motor cortex or spinal cord, we conclude that calcium entry through CaV1.2 is a critical survival signal for a subpopulation of callosal OPCs but not for all OPCs in the mature CNS.
Collapse
Affiliation(s)
- Kimberley A Pitman
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | - Raphael Ricci
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | - Robert Gasperini
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia.,School of Medicine, University of Tasmania, Hobart, Australia
| | - Shannon Beasley
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | - Macarena Pavez
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | - Jac Charlesworth
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | - Lisa Foa
- School of Medicine, University of Tasmania, Hobart, Australia
| | - Kaylene M Young
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| |
Collapse
|
17
|
Salveson I, Anderson DE, Hell JW, Ames JB. Chemical shift assignments of a calmodulin intermediate with two Ca 2+ bound in complex with the IQ-motif of voltage-gated Ca 2+ channels (Ca V1.2). Biomol NMR Assign 2019; 13:233-237. [PMID: 30788773 PMCID: PMC6440834 DOI: 10.1007/s12104-019-09883-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Accepted: 02/16/2019] [Indexed: 06/09/2023]
Abstract
Calcium-dependent inactivation (CDI) of neuronal voltage-gated Ca2+ channels (CaV1.2) is important for synaptic plasticity, which is associated with learning and memory. The Ca2+-dependent binding of calmodulin (CaM) to CaV1.2 is essential for CDI. Here we report NMR assignments for a CaM mutant (D21A/D23A/D25A/E32Q/D57A/D59A/N61A/E68Q, called CaMEF12) that contains two Ca2+ bound at the third and fourth EF-hands (EF3 and EF4) and is bound to the IQ-motif (residues 1644-1665) from CaV1.2 (BMRB accession no. 27692).
Collapse
Affiliation(s)
- Ian Salveson
- Department of Chemistry, University of California, 95616, Davis, CA, USA
| | - David E Anderson
- Department of Chemistry, University of California, 95616, Davis, CA, USA
| | - Johannes W Hell
- Department of Pharmacology, University of California, 95616, Davis, CA, USA
| | - James B Ames
- Department of Chemistry, University of California, 95616, Davis, CA, USA.
| |
Collapse
|
18
|
Mundhenk J, Fusi C, Kreutz MR. Caldendrin and Calneurons-EF-Hand CaM-Like Calcium Sensors With Unique Features and Specialized Neuronal Functions. Front Mol Neurosci 2019; 12:16. [PMID: 30787867 PMCID: PMC6372560 DOI: 10.3389/fnmol.2019.00016] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Accepted: 01/17/2019] [Indexed: 01/02/2023] Open
Abstract
The calmodulin (CaM)-like Ca2+-sensor proteins caldendrin, calneuron-1 and -2 are members of the neuronal calcium-binding protein (nCaBP)-family, a family that evolved relatively late during vertebrate evolution. All three proteins are abundant in brain but show a strikingly different subcellular localization. Whereas caldendrin is enriched in the postsynaptic density (PSD), calneuron-1 and -2 accumulate at the trans-Golgi-network (TGN). Caldendrin exhibit a unique bipartite structure with a basic and proline-rich N-terminus while calneurons are the only EF-Hand CaM-like transmembrane proteins. These uncommon structural features come along with highly specialized functions of calneurons in Golgi-to-plasma-membrane trafficking and for caldendrin in actin-remodeling in dendritic spine synapses. In this review article, we will provide a synthesis of available data on the structure and biophysical properties of all three proteins. We will then discuss their cellular function with special emphasis on synaptic neurotransmission. Finally, we will summarize the evidence for a role of these proteins in neuropsychiatric disorders.
Collapse
Affiliation(s)
- Jennifer Mundhenk
- RG Neuroplasticity, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Camilla Fusi
- RG Neuroplasticity, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Michael R Kreutz
- RG Neuroplasticity, Leibniz Institute for Neurobiology, Magdeburg, Germany.,Leibniz Group "Dendritic Organelles and Synaptic Function", Center for Molecular Neurobiology, ZMNH, Hamburg, Germany
| |
Collapse
|
19
|
De La Mata A, Tajada S, O'Dwyer S, Matsumoto C, Dixon RE, Hariharan N, Moreno CM, Santana LF. BIN1 Induces the Formation of T-Tubules and Adult-Like Ca 2+ Release Units in Developing Cardiomyocytes. Stem Cells 2018; 37:54-64. [PMID: 30353632 PMCID: PMC6312737 DOI: 10.1002/stem.2927] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Revised: 08/29/2018] [Accepted: 09/22/2018] [Indexed: 12/26/2022]
Abstract
Human embryonic stem cell-derived cardiomyocytes (hESC-CMs) are at the center of new cell-based therapies for cardiac disease, but may also serve as a useful in vitro model for cardiac cell development. An intriguing feature of hESC-CMs is that although they express contractile proteins and have sarcomeres, they do not develop transverse-tubules (T-tubules) with adult-like Ca2+ release units (CRUs). We tested the hypothesis that expression of the protein BIN1 in hESC-CMs promotes T-tubules formation, facilitates CaV 1.2 channel clustering along the tubules, and results in the development of stable CRUs. Using electrophysiology, [Ca2+ ]i imaging, and super resolution microscopy, we found that BIN1 expression induced T-tubule development in hESC-CMs, while increasing differentiation toward a more ventricular-like phenotype. Voltage-gated CaV 1.2 channels clustered along the surface sarcolemma and T-tubules of hESC-CM. The length and width of the T-tubules as well as the expression and size of CaV 1.2 clusters grew, as BIN1 expression increased and cells matured. BIN1 expression increased CaV 1.2 channel activity and the probability of coupled gating within channel clusters. Interestingly, BIN1 clusters also served as sites for sarcoplasmic reticulum (SR) anchoring and stabilization. Accordingly, BIN1-expressing cells had more CaV 1.2-ryanodine receptor junctions than control cells. This was associated with larger [Ca2+ ]i transients during excitation-contraction coupling. Our data support the view that BIN1 is a key regulator of T-tubule formation and CaV 1.2 channel delivery. By studying the role of BIN1 during the differentiation of hESC-CMs, we show that BIN1 is also important for CaV 1.2 channel clustering, junctional SR organization, and the establishment of excitation-contraction coupling. Stem Cells 2019;37:54-64.
Collapse
Affiliation(s)
- Ana De La Mata
- Department of Physiology & Membrane Biology, University of California School of Medicine, Davis, California, USA
| | - Sendoa Tajada
- Department of Physiology & Membrane Biology, University of California School of Medicine, Davis, California, USA
| | - Samantha O'Dwyer
- Department of Physiology & Membrane Biology, University of California School of Medicine, Davis, California, USA
| | - Collin Matsumoto
- Department of Physiology & Membrane Biology, University of California School of Medicine, Davis, California, USA
| | - Rose E Dixon
- Department of Physiology & Membrane Biology, University of California School of Medicine, Davis, California, USA
| | - Nirmala Hariharan
- Department of Pharmacology, University of California School of Medicine, Davis, California, USA
| | - Claudia M Moreno
- Department of Physiology & Membrane Biology, University of California School of Medicine, Davis, California, USA
| | - Luis Fernando Santana
- Department of Physiology & Membrane Biology, University of California School of Medicine, Davis, California, USA
| |
Collapse
|
20
|
Meza U, Beqollari D, Bannister RA. Molecular mechanisms and physiological relevance of RGK proteins in the heart. Acta Physiol (Oxf) 2018; 222:e13016. [PMID: 29237245 DOI: 10.1111/apha.13016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Revised: 12/05/2017] [Accepted: 12/06/2017] [Indexed: 12/19/2022]
Abstract
The primary route of Ca2+ entry into cardiac myocytes is via 1,4-dihydropyridine-sensitive, voltage-gated L-type Ca2+ channels. Ca2+ influx through these channels influences duration of action potential and engages excitation-contraction (EC) coupling in both the atria and the myocardium. Members of the RGK (Rad, Rem, Rem2 and Gem/Kir) family of small GTP-binding proteins are potent, endogenously expressed inhibitors of cardiac L-type channels. Although much work has focused on the molecular mechanisms by which RGK proteins inhibit the CaV 1.2 and CaV 1.3 L-type channel isoforms that expressed in the heart, their impact on greater cardiac function is only beginning to come into focus. In this review, we summarize recent findings regarding the influence of RGK proteins on normal cardiac physiology and the pathological consequences of aberrant RGK activity.
Collapse
Affiliation(s)
- U. Meza
- Departamento de Fisiología y Biofísica; Facultad de Medicina; Universidad Autónoma de San Luis Potosí; San Luis Potosí México
| | - D. Beqollari
- Department of Medicine-Cardiology Division; University of Colorado School of Medicine; Aurora CO USA
| | - R. A. Bannister
- Department of Medicine-Cardiology Division; University of Colorado School of Medicine; Aurora CO USA
| |
Collapse
|
21
|
Sahu G, Asmara H, Zhang FX, Zamponi GW, Turner RW. Activity-Dependent Facilitation of Ca V1.3 Calcium Channels Promotes KCa3.1 Activation in Hippocampal Neurons. J Neurosci 2017; 37:11255-70. [PMID: 29038242 DOI: 10.1523/JNEUROSCI.0967-17.2017] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Revised: 10/02/2017] [Accepted: 10/07/2017] [Indexed: 11/21/2022] Open
Abstract
CaV1 L-type calcium channels are key to regulating neuronal excitability, with the range of functional roles enhanced by interactions with calmodulin, accessory proteins, or CaMKII that modulate channel activity. In hippocampal pyramidal cells, a prominent elevation of CaV1 activity is apparent in late channel openings that can last for seconds following a depolarizing stimulus train. The current study tested the hypothesis that a reported interaction among CaV1.3 channels, the scaffolding protein densin, and CaMKII could generate a facilitation of channel activity that outlasts a depolarizing stimulus. We found that CaV1.3 but not CaV1.2 channels exhibit a long-duration calcium-dependent facilitation (L-CDF) that lasts up to 8 s following a brief 50 Hz stimulus train, but only when coexpressed with densin and CaMKII. To test the physiological role for CaV1.3 L-CDF, we coexpressed the intermediate-conductance KCa3.1 potassium channel, revealing a strong functional coupling to CaV1.3 channel activity that was accentuated by densin and CaMKII. Moreover, the CaV1.3-densin-CaMKII interaction gave rise to an outward tail current of up to 8 s duration following a depolarizing stimulus in both tsA-201 cells and male rat CA1 pyramidal cells. A slow afterhyperpolarization in pyramidal cells was reduced by a selective block of CaV1 channels by isradipine, a CaMKII blocker, and siRNA knockdown of densin, and spike frequency increased upon selective block of CaV1 channel conductance. The results are important in revealing a CaV1.3-densin-CaMKII interaction that extends the contribution of CaV1.3 calcium influx to a time frame well beyond a brief input train.SIGNIFICANCE STATEMENT CaV1 L-type calcium channels play a key role in regulating the output of central neurons by providing calcium influx during repetitive inputs. This study identifies a long-duration calcium-dependent facilitation (L-CDF) of CaV1.3 channels that depends on the scaffolding protein densin and CaMKII and that outlasts a depolarizing stimulus by seconds. We further show a tight functional coupling between CaV1.3 calcium influx and the intermediate-conductance KCa3.1 potassium channel that promotes an outward tail current of up to 8 s following a depolarizing stimulus. Tests in CA1 hippocampal pyramidal cells reveal that a slow AHP is reduced by blocking different components of the CaV1.3-densin-CaMKII interaction, identifying an important role for CaV1.3 L-CDF in regulating neuronal excitability.
Collapse
|
22
|
Benmocha Guggenheimer A, Almagor L, Tsemakhovich V, Tripathy DR, Hirsch JA, Dascal N. Interactions between N and C termini of α1C subunit regulate inactivation of CaV1.2 L-type Ca(2+) channel. Channels (Austin) 2016; 10:55-68. [PMID: 26577286 DOI: 10.1080/19336950.2015.1108499] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Abstract
The modulation and regulation of voltage-gated Ca(2+) channels is affected by the pore-forming segments, the cytosolic parts of the channel, and interacting intracellular proteins. In this study we demonstrate a direct physical interaction between the N terminus (NT) and C terminus (CT) of the main subunit of the L-type Ca(2+) channel CaV1.2, α1C, and explore the importance of this interaction for the regulation of the channel. We used biochemistry to measure the strength of the interaction and to map the location of the interaction sites, and electrophysiology to investigate the functional impact of the interaction. We show that the full-length NT (amino acids 1-154) and the proximal (close to the plasma membrane) part of the CT, pCT (amino acids 1508-1669) interact with sub-micromolar to low-micromolar affinity. Calmodulin (CaM) is not essential for the binding. The results further suggest that the NT-CT interaction regulates the channel's inactivation, and that Ca(2+), presumably through binding to calmodulin (CaM), reduces the strength of NT-CT interaction. We propose a molecular mechanism in which NT and CT of the channel serve as levers whose movements regulate inactivation by promoting changes in the transmembrane core of the channel via S1 (NT) or S6 (pCT) segments of domains I and IV, accordingly, and not as a kind of pore blocker. We hypothesize that Ca(2+)-CaM-induced changes in NT-CT interaction may, in part, underlie the acceleration of CaV1.2 inactivation induced by Ca(2+) entry into the cell.
Collapse
Affiliation(s)
- Adva Benmocha Guggenheimer
- a Department of Physiology and Pharmacology ; Sackler School of Medicine; Sagol School of Neuroscience ; Tel Aviv , Israel
| | - Lior Almagor
- b Department of Biochemistry & Molecular Biology ; Institute of Structural Biology, George S Weiss Faculty of Life Sciences; Sagol School of Neuroscience; Tel Aviv University ; Tel Aviv , Israel.,c Present address: Department of Structural Biology , Stanford University, School of Medicine ; Stanford , CA USA
| | - Vladimir Tsemakhovich
- a Department of Physiology and Pharmacology ; Sackler School of Medicine; Sagol School of Neuroscience ; Tel Aviv , Israel
| | - Debi Ranjan Tripathy
- b Department of Biochemistry & Molecular Biology ; Institute of Structural Biology, George S Weiss Faculty of Life Sciences; Sagol School of Neuroscience; Tel Aviv University ; Tel Aviv , Israel
| | - Joel A Hirsch
- b Department of Biochemistry & Molecular Biology ; Institute of Structural Biology, George S Weiss Faculty of Life Sciences; Sagol School of Neuroscience; Tel Aviv University ; Tel Aviv , Israel
| | - Nathan Dascal
- a Department of Physiology and Pharmacology ; Sackler School of Medicine; Sagol School of Neuroscience ; Tel Aviv , Israel
| |
Collapse
|
23
|
Beqollari D, Bannister RA. Defining the MO's of RGK proteins. Channels (Austin) 2016; 10:333-335. [PMID: 27249780 DOI: 10.1080/19336950.2016.1192845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Affiliation(s)
- Donald Beqollari
- a Department of Medicine-Cardiology Division , University of Colorado School of Medicine , Aurora , CO , USA
| | - Roger A Bannister
- a Department of Medicine-Cardiology Division , University of Colorado School of Medicine , Aurora , CO , USA
| |
Collapse
|
24
|
Ávila-Medina J, Calderón-Sánchez E, González-Rodríguez P, Monje-Quiroga F, Rosado JA, Castellano A, Ordóñez A, Smani T. Orai1 and TRPC1 Proteins Co-localize with CaV1.2 Channels to Form a Signal Complex in Vascular Smooth Muscle Cells. J Biol Chem 2016; 291:21148-21159. [PMID: 27535226 DOI: 10.1074/jbc.m116.742171] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Indexed: 11/06/2022] Open
Abstract
Voltage-dependent CaV1.2 L-type Ca2+ channels (LTCC) are the main route for calcium entry in vascular smooth muscle cells (VSMC). Several studies have also determined the relevant role of store-operated Ca2+ channels (SOCC) in vascular tone regulation. Nevertheless, the role of Orai1- and TRPC1-dependent SOCC in vascular tone regulation and their possible interaction with CaV1.2 are still unknown. The current study sought to characterize the co-activation of SOCC and LTCC upon stimulation by agonists, and to determine the possible crosstalk between Orai1, TRPC1, and CaV1.2. Aorta rings and isolated VSMC obtained from wild type or smooth muscle-selective conditional CaV1.2 knock-out (CaV1.2KO) mice were used to study vascular contractility, intracellular Ca2+ mobilization, and distribution of ion channels. We found that serotonin (5-HT) or store depletion with thapsigargin (TG) enhanced intracellular free Ca2+ concentration ([Ca2+]i) and stimulated aorta contraction. These responses were sensitive to LTCC and SOCC inhibitors. Also, 5-HT- and TG-induced responses were significantly attenuated in CaV1.2KO mice. Furthermore, hyperpolarization induced with cromakalim or valinomycin significantly reduced both 5-HT and TG responses, whereas these responses were enhanced with LTCC agonist Bay-K-8644. Interestingly, in situ proximity ligation assay revealed that CaV1.2 interacts with Orai1 and TRPC1 in untreated VSMC. These interactions enhanced significantly after stimulation of cells with 5-HT and TG. Therefore, these data indicate for the first time a functional interaction between Orai1, TRPC1, and CaV1.2 channels in VSMC, confirming that upon agonist stimulation, vessel contraction involves Ca2+ entry due to co-activation of Orai1- and TRPC1-dependent SOCC and LTCC.
Collapse
Affiliation(s)
- Javier Ávila-Medina
- From the Departamento de Fisiología Médica y Biofísica and Groupo de Fisiopatología Cardiovascular, Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, 41013 Sevilla, Spain
| | - Eva Calderón-Sánchez
- Groupo de Fisiopatología Cardiovascular, Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, 41013 Sevilla, Spain
| | | | - Francisco Monje-Quiroga
- the Department of Neurophysiology and Neuropharmacology, Center for Physiology and Pharmacology, Medical University of Vienna, 1090 Wien, Austria, and
| | - Juan Antonio Rosado
- the Departamento de Fisiología, Universidad de Extremadura, 10071 Cáceres, Spain
| | | | - Antonio Ordóñez
- Groupo de Fisiopatología Cardiovascular, Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, 41013 Sevilla, Spain
| | - Tarik Smani
- From the Departamento de Fisiología Médica y Biofísica and Groupo de Fisiopatología Cardiovascular, Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, 41013 Sevilla, Spain,
| |
Collapse
|
25
|
Dahl GP, Conner GE, Qiu F, Wang J, Spindler E, Campagna JA, Larsson HP. High affinity complexes of pannexin channels and L-type calcium channel splice-variants in human lung: Possible role in clevidipine-induced dyspnea relief in acute heart failure. EBioMedicine 2016; 10:291-7. [PMID: 27349457 DOI: 10.1016/j.ebiom.2016.06.027] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Revised: 06/20/2016] [Accepted: 06/20/2016] [Indexed: 12/02/2022] Open
Abstract
Clevidipine, a dihydropyridine (DHP) analogue, lowers blood pressure (BP) by inhibiting l-type calcium channels (CaV1.2; gene CACNA1C) predominantly located in vascular smooth muscle (VSM). However, clinical observations suggest that clevidipine acts by a more complex mechanism. Clevidipine more potently reduces pulmonary vascular resistance (PVR) than systemic vascular resistance and its spectrum of effects on PVR are not shared by other DHPs. Clevidipine has potent spasmolytic effects in peripheral arteries at doses that are sub-clinical for BP lowering and, in hypertensive acute heart failure, clevidipine, but not other DHPs, provides dyspnea relief, partially independent of BP reduction. These observations suggest that a molecular variation in CaV1.2 may exist which confers unique pharmacology to different DHPs. We sequenced CACNA1C transcripts from human lungs and measured their affinity for clevidipine. Human lung tissue contains CACNA1C mRNA with many different splice variations. CaV1.2 channels with a specific combination of variable exons showed higher affinity for clevidipine, well below the concentration associated with BP reduction. Co-expression with pannexin 1 further increased the clevidipine affinity for this CaV1.2 splice variant. A high-affinity splice variant of CaV1.2 in combination with pannexin 1 could underlie the selective effects of clevidipine on pulmonary arterial pressure and on dyspnea. Research in Context Clevidipine lowers blood pressure by inhibiting calcium channels in vascular smooth muscle. In patients with acute heart failure, clevidipine was shown to relieve breathing problems. This was only partially related to the blood pressure lowering actions of clevidipine and not conferred by another calcium channel inhibitor. We here found calcium channel variants in human lung that are more selectively inhibited by clevidipine, especially when associated with pannexin channels. This study gives a possible mechanism for clevidipine's relief of breathing problems and supports future clinical trials testing the role of clevidipine in the treatment of acute heart failure. CaV1.2 splice variants are found in human lung that have increased affinity for clevidipine. Co-expression of CaV1.2 splice variant with Pannexin 1 further increases affinity for clevidipine but not for nicardipine. Study supports future clinical trials testing the role of clevidipine in the treatment of acute hypertensive heart failure.
Collapse
|
26
|
Abstract
Rad/Rem/Rem2/Gem (RGK) proteins are Ras-like GTPases that potently inhibit all high-voltage-gated calcium (CaV1/CaV2) channels and are, thus, well-positioned to tune diverse physiological processes. Understanding how RGK proteins inhibit CaV channels is important for perspectives on their (patho)physiological roles and could advance their development and use as genetically-encoded CaV channel blockers. We previously reported that Rem can block surface CaV1.2 channels in 2 independent ways that engage distinct components of the channel complex: (1) by binding auxiliary β subunits (β-binding-dependent inhibition, or BBD); and (2) by binding the pore-forming α1C subunit N-terminus (α1C-binding-dependent inhibition, or ABD). By contrast, Gem uses only the BBD mechanism to block CaV1.2. Rem molecular determinants required for BBD CaV1.2 inhibition are the distal C-terminus and the guanine nucleotide binding G-domain which interact with the plasma membrane and CaVβ, respectively. However, Rem determinants for ABD CaV1.2 inhibition are unknown. Here, combining fluorescence resonance energy transfer, electrophysiology, systematic truncations, and Rem/Gem chimeras we found that the same Rem distal C-terminus and G-domain also mediate ABD CaV1.2 inhibition, but with different interaction partners. Rem distal C-terminus interacts with α1C N-terminus to anchor the G-domain which likely interacts with an as-yet-unidentified site. In contrast to some previous studies, neither the C-terminus of Rem nor Gem was sufficient to inhibit CaV1/CaV2 channels. The results reveal that similar molecular determinants on Rem are repurposed to initiate 2 independent mechanisms of CaV1.2 inhibition.
Collapse
Affiliation(s)
- Akil A Puckerin
- a Department of Pharmacology & Molecular Signaling , Columbia University , New York , NY , USA
| | - Donald D Chang
- b Department of Physiology & Cellular Biophysics , Columbia University , New York , NY , USA
| | - Prakash Subramanyam
- b Department of Physiology & Cellular Biophysics , Columbia University , New York , NY , USA
| | - Henry M Colecraft
- a Department of Pharmacology & Molecular Signaling , Columbia University , New York , NY , USA.,b Department of Physiology & Cellular Biophysics , Columbia University , New York , NY , USA
| |
Collapse
|
27
|
Turner M, Anderson DE, Rajan S, Hell JW, Ames JB. Chemical shift assignments of the C-terminal EF-hand domain of α-actinin-1. Biomol NMR Assign 2016; 10:219-222. [PMID: 26861220 PMCID: PMC4789133 DOI: 10.1007/s12104-016-9670-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Accepted: 02/05/2016] [Indexed: 06/05/2023]
Abstract
The regulation and localization of the neuronal voltage gated Ca(2+) channel CaV1.2 is important for synaptic plasticity associated with learning and memory. The cytoskeletal protein, α-actinin-1 is known to interact with CaV1.2 and stabilize its localization at the postsynaptic membrane. Here we report both backbone and sidechain NMR assignments for the C-terminal EF-hands (EF3 and EF4) of α-actinin-1 (residues 824-892, called ACTN_EF34) bound to the IQ-motif (residues 1644-1665) from CaV1.2 (BMRB accession no. 25902).
Collapse
Affiliation(s)
- Matthew Turner
- Department of Chemistry, University of California, Davis, Davis, CA, 95616, USA
| | - David E Anderson
- Department of Chemistry, University of California, Davis, Davis, CA, 95616, USA
| | - Sahana Rajan
- Department of Chemistry, University of California, Davis, Davis, CA, 95616, USA
| | - Johannes W Hell
- Department of Pharmacology, University of California, Davis, Davis, CA, 95616, USA
| | - James B Ames
- Department of Chemistry, University of California, Davis, Davis, CA, 95616, USA.
| |
Collapse
|
28
|
Buraei Z, Lee HK, Elmslie KS. Single channel measurements demonstrate the voltage dependence of permeation through N-type and L-type CaV channels. Channels (Austin) 2015; 9:50-5. [PMID: 25664681 DOI: 10.4161/19336950.2014.991606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The delivery of Ca2+ into cells by CaV channels provides the trigger for many cellular actions, such as cardiac muscle contraction and neurotransmitter release. Thus, a full understanding of Ca2+ permeation through these channels is critical. Using whole-cell voltage-clamp recordings, we recently demonstrated that voltage modulates the apparent affinity of N-type (CaV2.2) channels for permeating Ca2+ and Ba2+ ions. While we took many steps to ensure the high fidelity of our recordings, problems can occur when CaV currents become large and fast, or when currents run down. Thus, we use here single channel recordings to further test the hypothesis that permeating ions interact with N-type channels in a voltage-dependent manner. We also examined L-type (CaV1.2) channels to determine if these channels also exhibit voltage-dependent permeation. Like our whole-cell data, we find that voltage modulates N-channel affinity for Ba2+ at voltages>0 mV, but has little or no effect at voltages<0 mV. Furthermore, we demonstrate that permeation through L-channel is also modulated by voltage. Thus, voltage-dependence may be a common feature of divalent cation permeation through CaV1 and CaV2 channels (i.e. high-voltage activated CaV channels). The voltage dependence of CaV1 channel permeation is likely a mechanism mediating sustained Ca2+ influx during the plateau phase of the cardiac action potential.
Collapse
Affiliation(s)
- Zafir Buraei
- a Department of Biology ; Pace University ; New York , NY USA
| | | | | |
Collapse
|
29
|
Pantazis A, Savalli N, Sigg D, Neely A, Olcese R. Functional heterogeneity of the four voltage sensors of a human L-type calcium channel. Proc Natl Acad Sci U S A 2014; 111:18381-6. [PMID: 25489110 DOI: 10.1073/pnas.1411127112] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Excitation-evoked Ca(2+) influx is the fastest and most ubiquitous chemical trigger for cellular processes, including neurotransmitter release, muscle contraction, and gene expression. The voltage dependence and timing of Ca(2+) entry are thought to be functions of voltage-gated calcium (CaV) channels composed of a central pore regulated by four nonidentical voltage-sensing domains (VSDs I-IV). Currently, the individual voltage dependence and the contribution to pore opening of each VSD remain largely unknown. Using an optical approach (voltage-clamp fluorometry) to track the movement of the individual voltage sensors, we discovered that the four VSDs of CaV1.2 channels undergo voltage-evoked conformational rearrangements, each exhibiting distinct voltage- and time-dependent properties over a wide range of potentials and kinetics. The voltage dependence and fast kinetic components in the activation of VSDs II and III were compatible with the ionic current properties, suggesting that these voltage sensors are involved in CaV1.2 activation. This view is supported by an obligatory model, in which activation of VSDs II and III is necessary to open the pore. When these data were interpreted in view of an allosteric model, where pore opening is intrinsically independent but biased by VSD activation, VSDs II and III were each found to supply ∼50 meV (∼2 kT), amounting to ∼85% of the total energy, toward stabilizing the open state, with a smaller contribution from VSD I (∼16 meV). VSD IV did not appear to participate in channel opening.
Collapse
|
30
|
Bonner TI. Should pharmacologists care about alternative splicing? IUPHAR Review 4. Br J Pharmacol 2014; 171:1231-40. [PMID: 24670145 DOI: 10.1111/bph.12526] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2013] [Revised: 10/27/2013] [Accepted: 11/13/2013] [Indexed: 11/29/2022] Open
Abstract
Alternative splicing of mRNAs occurs in the majority of human genes, and most differential splicing results in different protein isoforms with possibly different functional properties. However, there are many reported splicing variations that may be quite rare, and not all combinatorially possible variants of a given gene are expressed at significant levels. Genes of interest to pharmacologists are frequently expressed at such low levels that they are not adequately represented in genome-wide studies of transcription. In single-gene studies, data are commonly available on the relative abundance and functional significance of individual alternatively spliced exons, but there are rarely data that quantitate the relative abundance of full-length transcripts and define which combinations of exons are significant. A number of criteria for judging the significance of splice variants and suggestions for their nomenclature are discussed.
Collapse
Affiliation(s)
- T I Bonner
- National Institute of Mental Health, Bethesda, MD, USA
| |
Collapse
|
31
|
Affiliation(s)
- Mark E Anderson
- From the University of Iowa Department of Internal Medicine, Division of Cardiovascular Medicine, Cardiovascular Research Center and the Department of Molecular Physiology and Biophysics, Carver College of Medicine, University of Iowa, Iowa City, IA
| |
Collapse
|
32
|
Subramanyam P, Chang DD, Fang K, Xie W, Marks AR, Colecraft HM. Manipulating L-type calcium channels in cardiomyocytes using split-intein protein transsplicing. Proc Natl Acad Sci U S A 2013; 110:15461-6. [PMID: 24003157 DOI: 10.1073/pnas.1308161110] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Manipulating expression of large genes (>6 kb) in adult cardiomyocytes is challenging because these cells are only efficiently transduced by viral vectors with a 4-7 kb packaging capacity. This limitation impedes understanding structure-function mechanisms of important proteins in heart. L-type calcium channels (LTCCs) regulate diverse facets of cardiac physiology including excitation-contraction coupling, excitability, and gene expression. Many important questions about how LTCCs mediate such multidimensional signaling are best resolved by manipulating expression of the 6.6 kb pore-forming α1C-subunit in adult cardiomyocytes. Here, we use split-intein-mediated protein transsplicing to reconstitute LTCC α1C-subunit from two distinct halves, overcoming the difficulty of expressing full-length α1C in cardiomyocytes. Split-intein-tagged α1C fragments encoding dihydropyridine-resistant channels were incorporated into adenovirus and reconstituted in cardiomyocytes. Similar to endogenous LTCCs, recombinant channels targeted to dyads, triggered Ca(2+) transients, associated with caveolin-3, and supported β-adrenergic regulation of excitation-contraction coupling. This approach lowers a longstanding technical hurdle to manipulating large proteins in cardiomyocytes.
Collapse
|
33
|
Zuccotti A, Lee SC, Campanelli D, Singer W, Satheesh SV, Patriarchi T, Geisler HS, Köpschall I, Rohbock K, Nothwang HG, Hu J, Hell JW, Schimmang T, Rüttiger L, Knipper M. L-type CaV1.2 deletion in the cochlea but not in the brainstem reduces noise vulnerability: implication for CaV1.2-mediated control of cochlear BDNF expression. Front Mol Neurosci 2013; 6:20. [PMID: 23950737 PMCID: PMC3739414 DOI: 10.3389/fnmol.2013.00020] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2013] [Accepted: 07/20/2013] [Indexed: 01/24/2023] Open
Abstract
Voltage-gated L-type Ca2+ channels (L-VGCCs) like CaV1.2 are assumed to play a crucial role for controlling release of trophic peptides including brain-derived neurotrophic factor (BDNF). In the inner ear of the adult mouse, besides the well-described L-VGCC CaV1.3, CaV1.2 is also expressed. Due to lethality of constitutive CaV1.2 knock-out mice, the function of this ion channel as well as its putative relationship to BDNF in the auditory system is entirely elusive. We recently described that BDNF plays a differential role for inner hair cell (IHC) vesicles release in normal and traumatized condition. To elucidate a presumptive role of CaV1.2 during this process, two tissue-specific conditional mouse lines were generated. To distinguish the impact of CaV1.2 on the cochlea from that on feedback loops from higher auditory centers CaV1.2 was deleted, in one mouse line, under the Pax2 promoter (CaV1.2Pax2) leading to a deletion in the spiral ganglion neurons, dorsal cochlear nucleus, and inferior colliculus. In the second mouse line, the Egr2 promoter was used for deleting CaV1.2 (CaV1.2Egr2) in auditory brainstem nuclei. In both mouse lines, normal hearing threshold and equal number of IHC release sites were observed. We found a slight reduction of auditory brainstem response wave I amplitudes in the CaV1.2Pax2 mice, but not in the CaV1.2Egr2 mice. After noise exposure, CaV1.2Pax2 mice had less-pronounced hearing loss that correlated with maintenance of ribbons in IHCs and less reduced activity in auditory nerve fibers, as well as in higher brain centers at supra-threshold sound stimulation. As reduced cochlear BDNF mRNA levels were found in CaV1.2Pax2 mice, we suggest that a CaV1.2-dependent step may participate in triggering part of the beneficial and deteriorating effects of cochlear BDNF in intact systems and during noise exposure through a pathway that is independent of CaV1.2 function in efferent circuits.
Collapse
Affiliation(s)
- Annalisa Zuccotti
- Molecular Physiology of Hearing, Hearing Research Center Tübingen, Department of Otolaryngology, University of Tübingen Tübingen, Germany
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|