31
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      The relationship between form and function throughout the history of excitation–contraction coupling

      review-article
      The Journal of General Physiology
      The Rockefeller University Press

      Read this article at

      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Franzini-Armstrong reviews the development of the excitation–contraction coupling field over time.

          Abstract

          The concept of excitation–contraction coupling is almost as old as Journal of General Physiology. It was understood as early as the 1940s that a series of stereotyped events is responsible for the rapid contraction response of muscle fibers to an initial electrical event at the surface. These early developments, now lost in what seems to be the far past for most young investigators, have provided an endless source of experimental approaches. In this Milestone in Physiology, I describe in detail the experiments and concepts that introduced and established the field of excitation–contraction coupling in skeletal muscle. More recent advances are presented in an abbreviated form, as readers are likely to be familiar with recent work in the field.

          Related collections

          Most cited references225

          • Record: found
          • Abstract: not found
          • Article: not found

          Extraction, purification and properties of aequorin, a bioluminescent protein from the luminous hydromedusan, Aequorea.

            Bookmark
            • Record: found
            • Abstract: found
            • Article: not found

            Junctophilins: a novel family of junctional membrane complex proteins.

            Junctional complexes between the plasma membrane (PM) and endoplasmic/sarcoplasmic reticulum (ER/ SR) are a common feature of all excitable cell types and mediate cross-talk between cell surface and intracellular ion channels. We have identified the junctophilins (JPs), a novel conserved family of proteins that are components of the junctional complexes. JPs are composed of a carboxy-terminal hydrophobic segment spanning the ER/SR membrane and a remaining cytoplasmic domain that shows specific affinity for the PM. In mouse, there are at least three JP subtypes: JP-1, -2, and -3. JP-2 is abundantly expressed in the heart, and mutant mice lacking JP-2 exhibited embryonic lethality. Cardiac myocytes from the mutant mice showed deficiency of the junctional membrane complexes and abnormal Ca2+ transients. Our results suggest that JPs are important components of junctional membrane complexes.
              Bookmark
              • Record: found
              • Abstract: found
              • Article: not found

              Rapid changes of mitochondrial Ca2+ revealed by specifically targeted recombinant aequorin.

              Introduction of Ca2+ indicators (photoproteins, fluorescent dyes) that can be trapped in the cytosolic compartment of living cells has yielded major advances in our knowledge of Ca2+ homeostasis. Ca2+ however regulates functions not only in the cytosol but also within various organelles where indicators have not yet been specifically targeted. Here we present a novel procedure by which the free Ca2+ concentration of mitochondria, [Ca2+]m, can be monitored continuously at rest and during stimulation. The complementary DNA for the Ca2+ sensitive photoprotein aequorin was fused in frame with that encoding a mitochondrial presequence. The hybrid cDNA was transfected into bovine endothelial cells and stable clones were obtained expressing variable amounts of mitochondrially targeted apoaequorin. The functional photoprotein could be reconstituted in intact cells by incubation with purified coelenterazine and [Ca2+]m could thus be monitored in situ. This allowed the unprecedented direct demonstration that agonist-stimulated elevations of cytosolic free Ca2+, [Ca2+]i, (measured in parallel with Fura-2) evoke rapid and transient increases of [Ca2+]m, which can be prevented by pretreatment with a mitochondrial uncoupler. The possibility of targeting aequorin to cellular organelles not only offers a new and powerful method for studying aspects of Ca2+ homeostasis that up to now could not be directly approached, but might also be used in the future as a tool to report in situ a variety of apparently unrelated phenomena of wide biological interest.
                Bookmark

                Author and article information

                Journal
                J Gen Physiol
                J. Gen. Physiol
                jgp
                jgp
                The Journal of General Physiology
                The Rockefeller University Press
                0022-1295
                1540-7748
                05 February 2018
                : 150
                : 2
                : 189-210
                Affiliations
                [1]Department of Cell and Developmental Biology, University of Pennsylvania School of Medicine, Philadelphia, PA
                Author notes
                Correspondence to Clara Franzini-Armstrong: armstroc@ 123456pennmedicine.upenn.edu
                Article
                201711889
                10.1085/jgp.201711889
                5806676
                29317466
                fa686ec0-a8ef-4d5f-b2fd-eb389093c2b3
                © 2018 Franzini-Armstrong

                This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see http://www.rupress.org/terms/). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 4.0 International license, as described at https://creativecommons.org/licenses/by-nc-sa/4.0/).

                History
                Categories
                Reviews
                Milestone in Physiology
                505
                515
                JGP 100th Anniversary

                Anatomy & Physiology
                Anatomy & Physiology

                Comments

                Comment on this article