Abstract

The long-term goal of Project 4 is to understand how the structure of the skeletal muscle calcium release channel (ryanodine receptor; RyR1) relates to its physical interactions with alpha2s-DHPR and SOCC to form reciprocally regulated Ca 2+release units (CRUs). Equally important cytoplasmic and lumenal interactions with CRU proteins are essential for tight regulation of SR Ca 2+ signaling and will be studied by Project 4 using biochemical, biophysical and cellular approaches to understand the underlying mechanisms relating RyR1 structure to function and its interactions with triadic proteins.
Aim I : Define biochemical and biophysical mechanisms underlying functional divergence of wild type (wt)RyR1, wtRyR3, and RyR1/3 chimeras. WtRyR3 and wtRyR1 differ in ability to couple with cqs-DHPR, and exhibit divergent channel gating kinetics, and modulation by physiological and pharmacological ligands. Differential interactions with FKBP12 or 12.6 at the valylprolyl core, as well as long-range allosteric influence may be responsible for these differences. We will define how altered RyR/FKBP interactions relate to divergent phenotypes.
Aim II. Elucidate how RyR1 conformation influences coupling with alpha1s,-DHPR and SOCC using point mutants and novel pharmacological agents. The mechanisms by which RyR1 conformation transmits important retrograde information to alpha1s-DHPR and store-operated Ca 2+channels (SOCCs) in myotubes will be defined.
Aim III : Define the structural and functional determinants by which Homer proteins regulate the gain of signaling events mediated by RyR1. We will elucidate how Homer proteins physically interact with RyR1 and modulate channel gain. Myotubes from mice lacking expression of one or more Homer protein(s) will be characterized to further define the role of Homer proteins in skeletal e-c coupling.
Aim I V. Define how deletion of CaM-binding domains of RyR1 (AA3614-3643) and CaM binding mutations of alpha1s-DHPR expressed in myotubes, alter their functional and physical interactions, and the influence of CaM on these interactions. Determinants for interactions between full-length RyR1 and (alpha1s-DHPR will be elucidated in dvsgenic and dvspedic myotubes.

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)
Type
Research Program Projects (P01)
Project #
2P01AR044750-06
Application #
6650539
Study Section
Special Emphasis Panel (ZAR1)
Project Start
2002-12-01
Project End
2007-11-30
Budget Start
Budget End
Support Year
6
Fiscal Year
2002
Total Cost
Indirect Cost

  Institution

Name
University of California Davis
Department
Type
DUNS #
City
State
Country
Zip Code

  Publications

Polster, Alexander; Perni, Stefano; Filipova, Dilyana et al. (2018) Junctional trafficking and restoration of retrograde signaling by the cytoplasmic RyR1 domain. J Gen Physiol 150:293-306
Yang, Zhong; Liu, Qiang; Mannix, Robert J et al. (2014) Mononuclear cells from dedifferentiation of mouse myotubes display remarkable regenerative capability. Stem Cells 32:2492-501
Manno, Carlo; Sztretye, Monika; Figueroa, Lourdes et al. (2013) Dynamic measurement of the calcium buffering properties of the sarcoplasmic reticulum in mouse skeletal muscle. J Physiol 591:423-42
Sheridan, David C; Moua, Ong; Lorenzon, Nancy M et al. (2012) Bimolecular fluorescence complementation and targeted biotinylation provide insight into the topology of the skeletal muscle Ca ( 2+) channel ?1a subunit. Channels (Austin) 6:26-40
Cai, Wen-Feng; Pritchard, Tracy; Florea, Stela et al. (2012) Ablation of junctin or triadin is associated with increased cardiac injury following ischaemia/reperfusion. Cardiovasc Res 94:333-41
Sztretye, Monika; Yi, Jianxun; Figueroa, Lourdes et al. (2011) Measurement of RyR permeability reveals a role of calsequestrin in termination of SR Ca(2+) release in skeletal muscle. J Gen Physiol 138:231-47
Chen, Fujun; Liu, Yun; Sugiura, Yoshie et al. (2011) Neuromuscular synaptic patterning requires the function of skeletal muscle dihydropyridine receptors. Nat Neurosci 14:570-7
Olojo, Rotimi O; Ziman, Andrew P; Hernández-Ochoa, Erick O et al. (2011) Mice null for calsequestrin 1 exhibit deficits in functional performance and sarcoplasmic reticulum calcium handling. PLoS One 6:e27036
Bannister, Roger A; Beam, Kurt G (2011) Properties of Na+ currents conducted by a skeletal muscle L-type Ca2+ channel pore mutant (SkEIIIK). Channels (Austin) 5:262-8
Estève, Eric; Eltit, José M; Bannister, Roger A et al. (2010) A malignant hyperthermia-inducing mutation in RYR1 (R163C): alterations in Ca2+ entry, release, and retrograde signaling to the DHPR. J Gen Physiol 135:619-28

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