Skip to content

Research at St Andrews

TRIC-B channels display labile gating: evidence from the TRIC-A knockout mouse model

Research output: Contribution to journalArticle

Author(s)

Elisa Venturi, Antoni Matyjaszkiewicz, Samantha Jane Pitt, Krasimira Tsaneva-Atanasova, Miyuki Nishi, Daiju Yamazaki, Hiroshi Takeshima, Rebecca Sitsapesan

School/Research organisations

Abstract

Sarcoplasmic/endoplasmic reticulum (SR) and nuclear membranes contain two related cation channels named TRIC-A and TRIC-B. In many tissues, both subtypes are co-expressed, making it impossible to distinguish the distinct single-channel properties of each subtype. We therefore incorporated skeletal muscle SR vesicles derived from Tric-a-knockout mice into bilayers in order to characterise the biophysical properties of native TRIC-B without possible misclassification of the channels as TRIC-A, and without potential distortion of functional properties by detergent purification protocols. The native TRIC-B channels were ideally selective for cations. In symmetrical 210 mM K+, the maximum (full) open channel level (199 pS) was equivalent to that observed when wild-type SR vesicles were incorporated into bilayers. Analysis of TRIC-B gating revealed complex and variable behaviour. Four main sub-conductance levels were observed at approximately 80 % (161 pS), 60 % (123 pS), 46 % (93 pS), and 30 % (60 pS) of the full open state. Seventy-five percent of the channels were voltage sensitive with Po being markedly reduced at negative holding potentials. The frequent, rapid transitions between TRIC-B sub-conductance states prevented development of reliable gating models using conventional single-channel analysis. Instead, we used mean-variance plots to highlight key features of TRIC-B gating in a more accurate and visually useful manner. Our study provides the first biophysical characterisation of native TRIC-B channels and indicates that this channel would be suited to provide counter current in response to Ca2+ release from the SR. Further experiments are required to distinguish the distinct functional properties of TRIC-A and TRIC-B and understand their individual but complementary physiological roles.

Close

Details

Original languageEnglish
Pages (from-to)1135-1148
JournalPflügers Archiv: European Journal of Physiology
Volume465
Issue number8
DOIs
Publication statusPublished - Aug 2013

    Research areas

  • Calcium-release, Ion channel, Excitation-contraction coupling, Sarcoplasmic reticulum

Discover related content
Find related publications, people, projects and more using interactive charts.

View graph of relations

Related by author

  1. A family of Type VI secretion system effector proteins that form ion-selective pores

    Mariano, G., Trunk, K., Williams, D. J., Monlezun, L., Strah, H., Pitt, S. J. & Coulthurst, S. J., 2 Dec 2019, In : Nature Communications. 10, p. 1-15 15 p., 5484.

    Research output: Contribution to journalArticle

  2. Reduced plasma magnesium levels in type-1 diabetes associate with prothrombotic changes in fibrin clotting and fibrinolysis

    Sobczak, A. I. S., Phoenix, F. A., Pitt, S. J., Ajjan, R. A. & Stewart, A. J., 11 Nov 2019, (Accepted/In press) In : Thrombosis and Haemostasis.

    Research output: Contribution to journalArticle

  3. Allosteric activation of an ion channel triggered by modification of mechanosensitive nano-pockets

    Kapsalis, C., Wang, B., El Mkami, H., Pitt, S. J., Schnell, J., Smith, T. K., Lippiat, J., Bode, B. E. & Pliotas, C., 10 Oct 2019, In : Nature Communications. 10, 14 p., 4619.

    Research output: Contribution to journalArticle

  4. Plasma non-esterified fatty acids contribute to increased coagulability in type-2 diabetes through altered plasma zinc speciation

    Sobczak, A. I. S., Katundu, K. G. H., Phoenix, F. A., Khazaipoul, S., Yu, R., Lampiao, F., Stefanowicz, F., Blindauer, C. A., Pitt, S. J., Smith, T. K., Ajjan, R. A. & Stewart, A. J., 28 Aug 2019, In : biorxiv. 38 p.

    Research output: Contribution to journalArticle

  5. Microlaser-based contractility sensing in single cardiomyocytes and whole hearts

    Schubert, M., Woolfson, L., Barnard, I. R. M., Morton, A., Casement, B., Robertson, G. B., Miles, G. B., Pitt, S. J., Tucker, C. S. & Gather, M. C., 22 Jul 2019, Novel Biophotonics Techniques and Applications V. Amelink, A. & Nadkarni, S. K. (eds.). SPIE, 110750C. (Progress in Biomedical Optics and Imaging - Proceedings of SPIE; vol. 11075).

    Research output: Chapter in Book/Report/Conference proceedingConference contribution

Related by journal

  1. Activity modes and modulation of the peptide-gated Na(+) channel of Helix neurones

    Green, KA. & Cottrell, G. A., Mar 2002, In : Pflügers Archiv: European Journal of Physiology. 443, 5-6, p. 813-821 9 p.

    Research output: Contribution to journalArticle

  2. Modulation of ligand-gated dopamine channels in Helix neurones

    Cottrell, G. A. & Green, KA., Jun 1997, In : Pflügers Archiv: European Journal of Physiology. 434, 3, p. 313-322 10 p.

    Research output: Contribution to journalArticle

ID: 48756481

Top