Deletion of small ankyrin 1 (sAnk1) isoforms results in structural and functional alterations in aging skeletal muscle fibers.

@article{Giacomello2015DeletionOS,
  title={Deletion of small ankyrin 1 (sAnk1) isoforms results in structural and functional alterations in aging skeletal muscle fibers.},
  author={Emiliana Giacomello and Marco Quarta and Cecilia Paolini and Roberta Squecco and Pina Fusco and Luana Toniolo and Bert Blaauw and Luca Formoso and Daniela Rossi and C. Birkenmeier and Luanne L Peters and Fabio Francini and Feliciano Protasi and Carlo Reggiani and Vincenzo Sorrentino},
  journal={American journal of physiology. Cell physiology},
  year={2015},
  volume={308 2},
  pages={
          C123-38
        }
}
Muscle-specific ankyrins 1 (sAnk1) are a group of small ankyrin 1 isoforms, of which sAnk1.5 is the most abundant. sAnk1 are localized in the sarcoplasmic reticulum (SR) membrane from where they interact with obscurin, a myofibrillar protein. This interaction appears to contribute to stabilize the SR close to the myofibrils. Here we report the structural and functional characterization of skeletal muscles from sAnk1 knockout mice (KO). Deletion of sAnk1 did not change the expression and… 
Calcium Homeostasis Is Modified in Skeletal Muscle Fibers of Small Ankyrin1 Knockout Mice
TLDR
Analysis of spontaneous Ca2+ release events (sparks) on saponin-permeabilized muscle fibers indicated that the frequency of sparks was significantly lower in fibers from 4-month-old KO mice compared to WT, and both the amplitude and spatial spread of sparks were significantly smaller in muscle fibers.
Identification of Small Ankyrin 1 as a Novel Sarco(endo)plasmic Reticulum Ca2+-ATPase 1 (SERCA1) Regulatory Protein in Skeletal Muscle*
TLDR
The results suggest that sAnk1 interacts with SERCA1 through its TM and cytoplasmic domains to regulateSERCA1 activity and modulate sequestration of Ca2+ in the sarcoplasmic reticulum lumen.
Interactions between small ankyrin 1 and sarcolipin coordinately regulate activity of the sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA1)
TLDR
It is indicated that sAnk1 and SLN can associate in the sarcoplasmic reticulum membrane and after exogenous expression in COS7 cells in vitro but that their association did not require endogenous SERCA2.
Impaired Intracellular Ca2+ Dynamics, M-Band and Sarcomere Fragility in Skeletal Muscles of Obscurin KO Mice
TLDR
Voltage clamp experiments show that a sarcoplasmic reticulum’s Ca2+ release and SERCA reuptake rates were decreased in muscle fibers from Obscn KO mice, suggesting that an impairment in intracellularCa2+ dynamics could explain the observed differences in the TTP and HRT in the diaphragm.
Exercise-induced alterations and loss of sarcomeric M-line organization in the diaphragm muscle of obscurin knockout mice.
TLDR
Results suggest that obscurin is required for the maintenance of morphological and ultrastructural integrity of skeletal muscle fibers against damage induced by intense mechanical stress and point to the diaphragm as the skeletal muscle most severely affected in obscur in-deficient mice.
Molecular determinants of homo- and heteromeric interactions of Junctophilin-1 at triads in adult skeletal muscle fibers
TLDR
Results suggest that the ability to establish homo- and heterodimeric interactions with resident JPHs may support the recruitment and stability of newly synthesized J PHs at triads in adult skeletal muscle fibers.
Organization of junctional sarcoplasmic reticulum proteins in skeletal muscle fibers
TLDR
The sarcoplasmic reticulum of striated muscles is specialized for releasing Ca2+ following sarcolemma depolarization in order to activate muscle contraction and, at the same time, participates to the assembly of the triadic junctional membrane complexes formed by the close apposition of one t-tubule, originated from the sar colemma, and two SR terminal cisternae.
Murine obscurin and Obsl1 have functionally redundant roles in sarcolemmal integrity, sarcoplasmic reticulum organization, and muscle metabolism
TLDR
It is shown that deletion of both Obsl1 and obscurin in skeletal muscle leads to severe alterations in sarcolemma organization, protein expression profiles, and cellular calcium handling, and these alterations affected muscle physiology and suggest redundant roles for Obsl 1 and obscuranin in murine muscle function.
...
1
2
3
...

References

SHOWING 1-10 OF 58 REFERENCES
Integrity of the network sarcoplasmic reticulum in skeletal muscle requires small ankyrin 1
TLDR
Results show that sAnk1 stabilizes the n SR and that its absence causes the nSR to fragment into distinct membrane compartments.
Localization of ank1.5 in the sarcoplasmic reticulum precedes that of SERCA and RyR: relationship with the organization of obscurin in developing sarcomeres
TLDR
It is inferred that exposure of some obscurin epitopes changes during skeletal muscle development, resulting in distinct, antibody-specific, localization pattern, and that this might affect the interaction with ank1.5.
Binding of an ankyrin-1 isoform to obscurin suggests a molecular link between the sarcoplasmic reticulum and myofibrils in striated muscles
TLDR
It is reported here that ank1.5, a small splice variant of the ank1 gene localized on the sarcoplasmic reticulum membrane, is capable of interacting with a sequence of 25 aa located at the COOH terminus of obscurin, a giant sarcomeric protein of ∼800 kD that binds to titin and has been proposed to mediate interactions between myofibrils and other cellular structures.
Small, Membrane-bound, Alternatively Spliced Forms of Ankyrin 1 Associated with the Sarcoplasmic Reticulum of Mammalian Skeletal Muscle
TLDR
It is proposed that, unlike the 210-kD form of Ank1, previously localized to the sarcolemma and believed to be a part of the supporting cytoskeleton, the small Ank1 isoforms may stabilize the sarcoplasmic reticulum by linking it to the contractile apparatus.
Obscurin is a ligand for small ankyrin 1 in skeletal muscle.
TLDR
These findings suggest that obscurin binds sAnk1, and are the first to document a specific and direct interaction between proteins of the sarcomere and the SR.
Obscurin determines the architecture of the longitudinal sarcoplasmic reticulum
TLDR
Obscurin knockout mice display centralized nuclei in skeletal muscles as a sign of mild myopathy, but have normal sarcomeric structure and preserved muscle function.
Reorganized stores and impaired calcium handling in skeletal muscle of mice lacking calsequestrin‐1
TLDR
Results demonstrate that CS1 is essential for the normal development of the SR and its calcium release units and for the storage and release of appropriate amounts of SR Ca2+.
Sequential stages in the age-dependent gradual formation and accumulation of tubular aggregates in fast twitch muscle fibers: SERCA and calsequestrin involvement
TLDR
The sequential stages leading to the initial appearance and maturation of TAs in EDL from male mice are investigated and it is suggested that the crystalline ATPase within the aggregates may be inactive.
...
1
2
3
4
5
...