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Autry JM, Svensson B, Carlson SF, Chen Z, Cornea RL, Thomas DD, Valberg SJ. Sarcoplasmic Reticulum from Horse Gluteal Muscle Is Poised for Enhanced Calcium Transport. Vet Sci 2021; 8:289. [PMID: 34941816 DOI: 10.3390/vetsci8120289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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: 10/20/2021] [Revised: 11/02/2021] [Accepted: 11/17/2021] [Indexed: 11/16/2022] Open
Abstract
We have analyzed the enzymatic activity of the sarcoplasmic reticulum (SR) Ca2+-transporting ATPase (SERCA) from the horse gluteal muscle. Horses are bred for peak athletic performance yet exhibit a high incidence of exertional rhabdomyolysis, with elevated levels of cytosolic Ca2+ proposed as a correlative linkage. We recently reported an improved protocol for isolating SR vesicles from horse muscle; these horse SR vesicles contain an abundant level of SERCA and only trace-levels of sarcolipin (SLN), the inhibitory peptide subunit of SERCA in mammalian fast-twitch skeletal muscle. Here, we report that the in vitro Ca2+ transport rate of horse SR vesicles is 2.3 ± 0.7-fold greater than rabbit SR vesicles, which express close to equimolar levels of SERCA and SLN. This suggests that horse myofibers exhibit an enhanced SR Ca2+ transport rate and increased luminal Ca2+ stores in vivo. Using the densitometry of Coomassie-stained SDS-PAGE gels, we determined that horse SR vesicles express an abundant level of the luminal SR Ca2+ storage protein calsequestrin (CASQ), with a CASQ-to-SERCA ratio about double that in rabbit SR vesicles. Thus, we propose that SR Ca2+ cycling in horse myofibers is enhanced by a reduced SLN inhibition of SERCA and by an abundant expression of CASQ. Together, these results suggest that horse muscle contractility and susceptibility to exertional rhabdomyolysis are promoted by enhanced SR Ca2+ uptake and luminal Ca2+ storage.
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Villiot N, Poulton AJ, Butcher ET, Daniels LR, Coggins A. Allometry of carbon and nitrogen content and growth rate in a diverse range of coccolithophores. J Plankton Res 2021; 43:511-526. [PMID: 34326702 PMCID: PMC8315238 DOI: 10.1093/plankt/fbab038] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 04/26/2021] [Accepted: 05/01/2021] [Indexed: 05/26/2023]
Abstract
As both photoautotrophs and calcifiers, coccolithophores play important roles in ecosystems and biogeochemical cycles. Though some species form blooms in high-latitude waters, low-latitude communities exhibit high diversity and niche diversification. Despite such diversity, our understanding of the clade relies on knowledge of Emiliana huxleyi. To address this, we examine carbon (C) and nitrogen (N) content of strains (n = 9) from the main families of the calcifying Haptophyceae, as well as allometry and cell size frequency across extant species. Coccolithophore cell size is constrained, with ~71% of 159 species smaller than 10 μm in diameter. Growth rates scale with cell biovolume (μ = 1.83 × cell volume-0.19), with an exponent close to metabolic theory. Organic carbon (C) per cell is lower than for other phytoplankton, providing a coccolithophore-specific relationship between cell organic C content and biovolume (pg C cell-1 = 0.30 × cell volume0.70). Organic C to N ratios (~8.3 mol:mol) are similar to other phytoplankton, implying little additional N cost for calcification and efficient retention and recycling of cell N. Our results support observations that coccolithophores are efficient competitors in low-nutrient conditions, able to photosynthesize, calcify and run the routine metabolic machinery necessary without any additional need for N relative to noncalcifying algae.
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Affiliation(s)
- Naomi Villiot
- The Lyell Centre for Earth and Marine Science and Technology, Heriot-Watt University, Research Avenue South, Edinburgh, EH14 4AS, UK
| | - Alex J Poulton
- The Lyell Centre for Earth and Marine Science and Technology, Heriot-Watt University, Research Avenue South, Edinburgh, EH14 4AS, UK
| | - Elizabeth T Butcher
- Ocean and Earth Science, National Oceanography Centre Southampton, University of Southampton, Waterfront Campus, Southampton, SO18 3ZH, UK
| | - Lucie R Daniels
- Ocean and Earth Science, National Oceanography Centre Southampton, University of Southampton, Waterfront Campus, Southampton, SO18 3ZH, UK
| | - Aimee Coggins
- Ocean and Earth Science, National Oceanography Centre Southampton, University of Southampton, Waterfront Campus, Southampton, SO18 3ZH, UK
- Atmospheric and Ocean Sciences, College of Life and Environmental Sciences, University of Exeter, Prince of Wales Road, Exeter EX4 4PS, UK
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Gomez NA. Using e-notebooks to explore biochemistry with an agricultural lens. Biochem Mol Biol Educ 2020; 48:667-669. [PMID: 33186489 DOI: 10.1002/bmb.21467] [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] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 08/21/2020] [Accepted: 09/09/2020] [Indexed: 06/11/2023]
Abstract
The interdisciplinary subject of agricultural biochemistry can provide an abundance of didactic opportunities for educators teaching biochemistry and molecular biology in secondary-level science courses. This is especially true in present times when virtual-learning strategies supersede in-person instruction and contemporary approaches are needed to engage students with relevant applications of science. In this communication, we discuss how pairing daily lessons in agricultural biochemistry with periodic e-notebook usage further refines this strategy by promoting content-retrieval and providing educators with formative feedback on student progress in a simple and inexpensive manner.
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Affiliation(s)
- Noe A Gomez
- Department of Science, Carpinteria High School, Carpinteria Unified School District, Carpinteria, California, USA
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Gomez NA, Robinson PH. From blood to milk: Graphical systems modeling in secondary-level biochemistry courses. Biochem Mol Biol Educ 2020; 48:535-537. [PMID: 32891069 DOI: 10.1002/bmb.21448] [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] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 08/12/2020] [Accepted: 08/21/2020] [Indexed: 06/11/2023]
Abstract
Given the present need for biochemistry and molecular biology educators to transform their courses into an online format, novel methods aimed at promoting student learning and engagement must be considered. Herein, we describe the integration of graphical systems modeling as a tool for introducing biochemistry to secondary-level students. We propose the use of graphic technologies as a way for students to create systems models that describe phenomena of life, such as lactation. Through these endeavors, educators can provide a virtual format for students to continue learning and completing assignments.
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Affiliation(s)
- Noe A Gomez
- Department of Science, Carpinteria High School, Carpinteria Unified School District, 1400 Linden Ave., Carpinteri, California, USA
| | - Peter H Robinson
- Department of Animal Science, University of California, Davis, California, USA
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van Hazel I, Dungan SZ, Hauser FE, Morrow JM, Endler JA, Chang BSW. A comparative study of rhodopsin function in the great bowerbird (Ptilonorhynchus nuchalis): Spectral tuning and light-activated kinetics. Protein Sci 2016; 25:1308-18. [PMID: 26889650 DOI: 10.1002/pro.2902] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [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: 01/11/2016] [Revised: 02/16/2016] [Accepted: 02/16/2016] [Indexed: 12/18/2022]
Abstract
Rhodopsin is the visual pigment responsible for initiating the phototransduction cascade in vertebrate rod photoreceptors. Although well-characterized in a few model systems, comparative studies of rhodopsin function, particularly for nonmammalian vertebrates are comparatively lacking. Bowerbirds are rare among passerines in possessing a key substitution, D83N, at a site that is otherwise highly conserved among G protein-coupled receptors. While this substitution is present in some dim-light adapted vertebrates, often accompanying another unusual substitution, A292S, its functional relevance in birds is uncertain. To investigate functional effects associated with these two substitutions, we use the rhodopsin gene from the great bowerbird (Ptilonorhynchus nuchalis) as a background for site-directed mutagenesis, in vitro expression and functional characterization. We also mutated these sites in two additional rhodopsins that do not naturally possess N83, chicken and bovine, for comparison. Both sites were found to contribute to spectral blue-shifts, but had opposing effects on kinetic rates. Substitutions at site 83 were found to primarily affect the kinetics of light-activated rhodopsin, while substitutions at site 292 had a larger impact on spectral tuning. The contribution of substitutions at site 83 to spectral tuning in particular depended on genetic background, but overall, the effects of substitutions were otherwise surprisingly additive, and the magnitudes of functional shifts were roughly similar across all three genetic backgrounds. By employing a comparative approach with multiple species, our study provides new insight into the joint impact of sites 83 and 292 on rhodopsin structure-function as well as their evolutionary significance for dim-light vision across vertebrates.
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Affiliation(s)
- Ilke van Hazel
- Department of Ecology and Evolutionary Biology, University of Toronto, Canada
| | - Sarah Z Dungan
- Department of Ecology and Evolutionary Biology, University of Toronto, Canada
| | - Frances E Hauser
- Department of Ecology and Evolutionary Biology, University of Toronto, Canada
| | - James M Morrow
- Department of Cell and Systems Biology, University of Toronto, Canada
| | - John A Endler
- Centre for Integrative Ecology, Deakin University, Australia
| | - Belinda S W Chang
- Department of Ecology and Evolutionary Biology, University of Toronto, Canada.,Department of Cell and Systems Biology, University of Toronto, Canada.,Centre for the Analysis of Genome Evolution and Function, University of Toronto, Canada
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Yuasa HJ, Mizuno K, Ball HJ. Low efficiency IDO2 enzymes are conserved in lower vertebrates, whereas higher efficiency IDO1 enzymes are dispensable. FEBS J 2015; 282:2735-45. [PMID: 25950090 DOI: 10.1111/febs.13316] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [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: 10/29/2014] [Revised: 04/01/2015] [Accepted: 04/30/2015] [Indexed: 12/16/2022]
Abstract
Indoleamine 2,3-dioxygenase (IDO) is a Trp-degrading enzyme that catalyzes the first step in the kynurenine pathway. Two IDO genes, IDO1 and IDO2, are found in vertebrates and the timing of the gene duplication giving rise to the genes has been controversial. In the present study, we report that several fishes and two turtles also have both IDO1 and IDO2. This represents definitive evidence for the gene duplication occurring before the divergence of vertebrates, with IDO1 having been lost in a number of lower vertebrate lineages. IDO2 enzymes have a relatively low affinity for l-Trp; however, Anolis carolinensis (lizard) IDO2 has an affinity for l-Trp comparable to mammalian IDO1 enzymes. We identified a Ser residue located in the distal heme pocket of IDO1 (distal-Ser) (corresponding to Ser167 of human IDO1) that is conserved in all IDO1 enzymes and the lizard IDO2. This residue is conserved as Thr (distal-Thr) in other IDO2 enzymes. Biochemical analyses, using IDO variants with either Ser or Thr substitutions, suggest that the distal-Ser change was crucial for the improvement in affinity for l-Trp in ancient IDO1. The ancestral IDO1 likely had a 'moderate' enzymatic efficiency for l-Trp, clearly higher than IDO2 but lower than mammalian IDO1. The distal-Ser of lizard IDO2 bestows a high affinity for l-Trp, however, this unique IDO2 has a low enzymatic efficiency because of its very low catalytic velocity. Thus, low efficiency IDO2 enzymes have been conserved throughout vertebrate evolution, whereas higher efficiency IDO1 enzymes are dispensable in many lower vertebrate lineages.
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Affiliation(s)
- Hajime J Yuasa
- Laboratory of Biochemistry, Department of Applied Science, Faculty of Science, National University Corporation Kochi University, Japan
| | - Keiko Mizuno
- Laboratory of Biochemistry, Department of Applied Science, Faculty of Science, National University Corporation Kochi University, Japan
| | - Helen J Ball
- Molecular Immunopathology Unit, Discipline of Pathology, School of Medical Sciences and Bosch Institute, University of Sydney, Australia
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Hanukoglu I. Proteopedia: Rossmann fold: A beta-alpha-beta fold at dinucleotide binding sites. Biochem Mol Biol Educ 2015; 43:206-9. [PMID: 25704928 DOI: 10.1002/bmb.20849] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Accepted: 11/14/2014] [Indexed: 05/04/2023]
Abstract
The Rossmann fold is one of the most common and widely distributed super-secondary structures. It is composed of a series of alternating beta strand (β) and alpha helical (α) segments wherein the β-strands are hydrogen bonded forming a β-sheet. The initial beta-alpha-beta (βαβ) fold is the most conserved segment of Rossmann folds. As this segment is in contact with the ADP portion of dinucleotides such as FAD, NAD, and NADP it is also called as an "ADP-binding βαβ fold". The Proteopedia entry on the Rossmann fold (Available at: http://proteopedia.org/w/Rossmann_fold) was generated to illustrate several structural aspects of super families of FAD and NAD(P) binding proteins: (1) The coenzymes FAD and NAD(P) share the basic adenosine diphosphate (ADP) structure. (2) The βαβ fold motif that is common to both FAD and NAD(P) binding enzymes accommodates the common ADP component of these two coenzymes. (3) In both FAD and NAD(P) binding sites, the tight turn between the first β-strand and the α-helix is in contact with the two phosphate groups of ADP. (4) This hairpin curve includes the first two conserved glycines (Gly-x-Gly) that allow the sharp turn of the polypeptide backbone. (5) The two β-strands of the βαβ fold may constitute the core of a larger β-sheet that may include up to seven β-strands generally in parallel orientation. (6) The structures of segments between additional strands vary greatly and may be composed of a variety of structures such as multiple short helices or coils.
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Affiliation(s)
- Israel Hanukoglu
- Faculty of Natural Sciences, Ariel University, Ariel, 40700, Israel
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