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Weiner AC, Chen HY, Roegner ME, Watson RD. Calcium signaling and regulation of ecdysteroidogenesis in crustacean Y-organs. Gen Comp Endocrinol 2021; 314:113901. [PMID: 34530000 DOI: 10.1016/j.ygcen.2021.113901] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 09/06/2021] [Accepted: 09/09/2021] [Indexed: 01/21/2023]
Abstract
Crustacean Y-organs secrete ecdysteroid molting hormones. Ecdysteroids are released in increased amount during premolt, circulate in hemolymph, and stimulate the events in target cells that lead to molting. During much of the molting cycle, ecdysteroid production is suppressed by molt-inhibiting hormone (MIH), a peptide neurohormone produced in the eyestalks. The suppressive effect of MIH is mediated by a cyclic nucleotide second messenger. A decrease in circulating MIH is associated with an increase in the hemolymphatic ecdysteroid titer during pre-molt. Nevertheless, it has long been hypothesized that a positive regulatory signal or stimulus is also involved in promoting ecdysteroidogenensis during premolt. Data reviewed here are consistent with the hypothesis that an intracellular Ca2+ signal provides that stimulus. Pharmacological agents that increase intracellular Ca2+ in Y-organs promote ecdysteroidogenesis, while agents that lower intracellular Ca2+ or disrupt Ca2+ signaling suppress ecdysteroidogenesis. Further, an increase in the hemolymphatic ecdysteroid titer after eyestalk ablation or during natural premolt is associated with an increase in intracellular free Ca2+ in Y-organ cells. Several lines of evidence suggest elevated intracellular calcium is linked to enhanced ecdysteroidogenesis through activation of Ca2+/calmodulin dependent cyclic nucleotide phosphodiesterase, thereby lowering intracellular cyclic nucleotide second messenger levels and promoting ecdysteroidogenesis. Results of transcriptomic studies show genes involved in Ca2+ signaling are well represented in Y-organs. Several recent studies have focused on Ca2+ transport proteins in Y-organs. Complementary DNAs encoding a plasma membrane Ca2+ ATPase (PMCA) and a sarcoplasmic/endoplasmic reticulum Ca2+ ATPase (SERCA) have been cloned from crab Y-organs. The relative abundance of PMCA and SERCA transcripts in Y-organs is elevated during premolt, a time when Ca2+ levels in Y-organs are likewise elevated. The results are consistent with the notion that these transport proteins act to maintain the Ca2+ gradient across the cell membrane and re-set the cell for future Ca2+ signals.
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Affiliation(s)
- Amanda C Weiner
- Department of Biology, University of Alabama at Birmingham, Birmingham, AL 35294, United States
| | - Hsiang-Yin Chen
- Department of Biology, University of Alabama at Birmingham, Birmingham, AL 35294, United States
| | - Megan E Roegner
- Department of Biology, University of Alabama at Birmingham, Birmingham, AL 35294, United States
| | - R Douglas Watson
- Department of Biology, University of Alabama at Birmingham, Birmingham, AL 35294, United States.
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Simonet Roda M, Ziegler A, Griesshaber E, Yin X, Rupp U, Greiner M, Henkel D, Häussermann V, Eisenhauer A, Laudien J, Schmahl WW. Terebratulide brachiopod shell biomineralization by mantle epithelial cells. J Struct Biol 2019; 207:136-157. [PMID: 31071428 DOI: 10.1016/j.jsb.2019.05.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 05/02/2019] [Accepted: 05/04/2019] [Indexed: 11/16/2022]
Abstract
To understand mineral transport pathways for shell secretion and to assess differences in cellular activity during mineralization, we imaged with TEM and FE-SEM ultrastructural characteristics of outer mantle epithelium (OME) cells. Imaging was carried out on Magellania venosa shells embedded/etched, chemically fixed/decalcified and high-pressure frozen/freeze-substituted samples from the commissure, central shell portions and from puncta. Imaging results are complemented with morphometric evaluations of volume fractions of membrane-bound organelles. At the commissure the OME consists of several layers of cells. These cells form oblique extensions that, in cross-section, are round below the primary layer and flat underneath fibres. At the commissure the OME is multi-cell layered, in central shell regions it is single-cell layered. When actively secreting shell carbonate extrapallial space is lacking, because OME cells are in direct contact with the calcite of the forming fibres. Upon termination of secretion, OME cells attach via apical hemidesmosomes to extracellular matrix membranes that line the proximal surface of fibres. At the commissure volume fractions for vesicles, mitochondria and lysosomes are higher relative to single-cell layered regions, whereas for endoplasmic-reticulum and Golgi apparatus there is no difference. FE-SEM, TEM imaging reveals the lack of extrapallial space between OME cells and developing fibres. In addition, there is no indication for an amorphous precursor within fibres when these are in active secretion mode. Accordingly, our results do not support transport of minerals by vesicles from cells to sites of mineralization, rather by transfer of carbonate ions via transport mechanisms associated with OME cell membranes.
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Affiliation(s)
- M Simonet Roda
- Department of Earth and Environmental Sciences, LMU, 80333 München, Germany.
| | - A Ziegler
- Central Facility for Electron Microscopy, University of Ulm, 89069 Ulm, Germany
| | - E Griesshaber
- Department of Earth and Environmental Sciences, LMU, 80333 München, Germany
| | - X Yin
- Department of Earth and Environmental Sciences, LMU, 80333 München, Germany
| | - U Rupp
- Central Facility for Electron Microscopy, University of Ulm, 89069 Ulm, Germany
| | - M Greiner
- Department of Earth and Environmental Sciences, LMU, 80333 München, Germany
| | - D Henkel
- Marine Biogeochemistry/Marine Systems, GEOMAR Helmholtz Centre for Ocean Research, 24148 Kiel, Germany
| | - V Häussermann
- Pontificia Universidad Católica de Valparaíso, Facultad de Recursos Naturales, Escuela de Ciencias del Mar, Avda. Brasil, 2950 Valparaíso, Chile; Huinay Scientific Field Station, Puerto Montt, Chile
| | - A Eisenhauer
- Marine Biogeochemistry/Marine Systems, GEOMAR Helmholtz Centre for Ocean Research, 24148 Kiel, Germany
| | - J Laudien
- Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, 27568 Bremerhaven, Germany
| | - W W Schmahl
- Department of Earth and Environmental Sciences, LMU, 80333 München, Germany
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Characterization of sarcoplasmic calcium binding protein (SCP) variants from freshwater crayfish Procambarus clarkii. Comp Biochem Physiol B Biochem Mol Biol 2011; 160:8-14. [PMID: 21530674 DOI: 10.1016/j.cbpb.2011.04.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2011] [Revised: 04/11/2011] [Accepted: 04/12/2011] [Indexed: 10/18/2022]
Abstract
Sarcoplasmic calcium binding protein (SCP) is an invertebrate EF-hand calcium buffering protein that has been proposed to fulfill a similar function in muscle relaxation as vertebrate parvalbumin. We have identified three SCP variants in the freshwater crayfish Procambarus clarkii. The variants (pcSCP1a, pcSCP1b, and pcSCP1c) differ across a 37 amino acid region that lies mainly between the second and third EF-hand calcium binding domains. We evaluated tissue distribution and response of the variants to cold exposure, a stress known to affect expression of parvalbumin. Expression patterns of the variants were not different and therefore do not provide a functional rationale for the polymorphism of pcSCP1. Compared to hepatopancreas, expression of pcSCP1 variants was 100,000-fold greater in axial abdominal muscle and 10-fold greater in cardiac muscle. Expression was 10-100 greater in fast-twitch deep flexor and extensor muscles compared to slow-twitch superficial flexor and extensors. In axial muscle, no significant changes of pcSCP1, calmodulin (CaM), or sarcoplasmic/endoplasmic reticulum Ca-ATPase (SERCA) expression were measured after one week of 4°C exposure. In contrast, large decreases of pcSCP1 were measured in cardiac muscle, with no changes in CaM or SERCA. Knockdown of pcSCP1 by dsRNA led to reduced muscle activity and decreased expression of SERCA. In summary, the pattern of pcSCP1 tissue expression is similar to parvalbumin, supporting a role in muscle contraction. However, the response of pcSCP1 to cold exposure differs from parvalbumin, suggesting possible functional divergence between the two proteins.
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Gillen CM, Gao Y, Niehaus-Sauter MM, Wylde MR, Wheatly MG. Elongation factor 1Bgamma (eEF1Bgamma) expression during the molting cycle and cold acclimation in the crayfish Procambarus clarkii. Comp Biochem Physiol B Biochem Mol Biol 2008; 150:170-6. [PMID: 18407536 DOI: 10.1016/j.cbpb.2008.02.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2008] [Revised: 02/26/2008] [Accepted: 02/26/2008] [Indexed: 02/04/2023]
Abstract
Eukaryotic elongation factor 1Bgamma (eEF1Bgamma) is a subunit of elongation factor 1 (EF1), which regulates the recruitment of amino acyl-tRNAs to the ribosome during protein synthesis in eukaryotes. In addition to structural roles within eEF1, eEF1Bgamma has properties which suggest sensory or regulatory activities. We have cloned eEF1Bgamma from axial abdominal muscle of freshwater crayfish, Procambarus clarkii. The predicted amino acid sequence has 66% identity to Locusta migratoria eEF1Bgamma and 65% identity to Artemia salina eEF1Bgamma. We measured eEF1Bgamma expression by real-time PCR, using the relative quantification method with 18s ribosomal RNA as an internal calibrator. eEF1Bgamma expression was lowest in gill, axial abdominal muscle, and hepatopancreas, and was highest in the antennal gland (5.7-fold above hepatopancreas) and cardiac muscle (7.8-fold above hepatopancreas). In axial abdominal muscle, eEF1Bgamma expression was 4.4-fold higher in premolt and 11.9 higher in postmolt compared to intermolt. In contrast, eEF1Bgamma was decreased or unchanged in epithelial tissues during pre- and postmolt. eEF1Bgamma expression in the hepatopancreas was 3.5-fold higher during intermolt compared to premolt and was unchanged in gill and antennal gland. No significant differences in eEF1Bgamma were found after 1 week of acclimation to 4 degrees C. These results show that eEF1Bgamma is regulated at the mRNA level with tissue-specific differences in expression patterns.
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