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Geddes JW, Bondada V, Croall DE, Rodgers DW, Gal J. Impaired activity and membrane association of most calpain-5 mutants causal for neovascular inflammatory vitreoretinopathy. Biochim Biophys Acta Mol Basis Dis 2023; 1869:166747. [PMID: 37207905 PMCID: PMC10332796 DOI: 10.1016/j.bbadis.2023.166747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 03/29/2023] [Accepted: 05/02/2023] [Indexed: 05/21/2023]
Abstract
Neovascular inflammatory vitreoretinopathy (NIV) is a rare eye disease that ultimately leads to complete blindness and is caused by mutations in the gene encoding calpain-5 (CAPN5), with six pathogenic mutations identified. In transfected SH-SY5Y cells, five of the mutations resulted in decreased membrane association, diminished S-acylation, and reduced calcium-induced autoproteolysis of CAPN5. CAPN5 proteolysis of the autoimmune regulator AIRE was impacted by several NIV mutations. R243, L244, K250 and the adjacent V249 are on β-strands in the protease core 2 domain. Conformational changes induced by Ca2+binding result in these β-strands forming a β-sheet and a hydrophobic pocket which docks W286 side chain away from the catalytic cleft, enabling calpain activation based on comparison with the Ca2+-bound CAPN1 protease core. The pathologic variants R243L, L244P, K250N, and R289W are predicted to disrupt the β-strands, β-sheet, and hydrophobic pocket, impairing calpain activation. The mechanism by which these variants impair membrane association is unclear. G376S impacts a conserved residue in the CBSW domain and is predicted to disrupt a loop containing acidic residues which may contribute to membrane binding. G267S did not impair membrane association and resulted in a slight but significant increase in autoproteolytic and proteolytic activity. However, G267S is also identified in individuals without NIV. Combined with the autosomal dominant pattern of NIV inheritance and evidence that CAPN5 may dimerize, the results are consistent with a dominant negative mechanism for the five pathogenic variants which resulted in impaired CAPN5 activity and membrane association and a gain-of-function for the G267S variant.
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Affiliation(s)
- James W Geddes
- Spinal Cord and Brain Injury Research Center (SCoBIRC), University of Kentucky, Lexington, KY 40536, USA; Department of Neuroscience, University of Kentucky, Lexington, KY 40536, USA.
| | - Vimala Bondada
- Spinal Cord and Brain Injury Research Center (SCoBIRC), University of Kentucky, Lexington, KY 40536, USA
| | - Dorothy E Croall
- Department of Molecular and Biomedical Sciences, University of Maine, Orono, ME 04469, USA.
| | - David W Rodgers
- Department of Molecular and Cellular Biochemistry and Center for Structural Biology, University of Kentucky, Lexington, KY 40536, USA.
| | - Jozsef Gal
- Spinal Cord and Brain Injury Research Center (SCoBIRC), University of Kentucky, Lexington, KY 40536, USA; Department of Neuroscience, University of Kentucky, Lexington, KY 40536, USA.
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Wu N, Zhang J, Ou W, Chen Y, Wang R, Li K, Sun XM, Li Y, Xu Q, Huang H. Transcriptome analysis of Rhizopus oryzae seed pellet formation using triethanolamine. BIOTECHNOLOGY FOR BIOFUELS 2021; 14:230. [PMID: 34863259 PMCID: PMC8645130 DOI: 10.1186/s13068-021-02081-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Accepted: 11/19/2021] [Indexed: 06/13/2023]
Abstract
Rhizopus oryzae (R. oryzae) can effectively produce organic acids, and its pellet formation in seed cultures has been shown to significantly enhance subsequent fermentation processes. Despite advances in strain development, simple and effective methods for inducing pellet morphology and a basic understanding of the mechanisms controlling this process could facilitate substantial increases in efficiency and product output. Here, we report that 1.5% triethanolamine (TEOA) in seed culture medium can activate the growth of R. oryzae spores in compact and uniform pellets which is optimal for fermentation conditions. Analysis of fermentation kinetics showed that the production of fumaric and L-malic acid increases 293% and 177%, respectively. Transcriptomic analysis revealed that exposure of R. oryzae to 1.5% TEOA during the seed culture activated the phosphatidylinositol and mitogen-activated protein kinase signaling pathways. Theses pathways subsequently stimulated the downstream carbohydrate-active synthases and hydrolases that required for cell wall component synthesis and reconstruction. Our results thus provide insight into the regulatory pathways controlling pellet morphology germane to the viability of seed cultures, and provide valuable reference data for subsequent optimization of organic acid fermentation by R. oryzae.
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Affiliation(s)
- Na Wu
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, China
| | - Jiahui Zhang
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, China
| | - Wen Ou
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, China
| | - Yaru Chen
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, China
| | - Ru Wang
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, China
| | - Ke Li
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, China
| | - Xiao-Man Sun
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, China
| | - Yingfeng Li
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, China
| | - Qing Xu
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, China.
| | - He Huang
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, China.
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Li L, He L, Wu B, Yu C, Zhao H, Zhou Y, Wang J, Zhu L. Structural Determinants for Light-Dependent Membrane Binding of a Photoswitchable Polybasic Domain. ACS Synth Biol 2021; 10:542-551. [PMID: 33689308 DOI: 10.1021/acssynbio.0c00571] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
OptoPB is an optogenetic tool engineered by fusion of the phosphoinositide (PI)-binding polybasic domain of Rit1 (Rit-PB) to a photoreactive light-oxygen-voltage (LOV) domain. OptoPB selectively and reversibly binds the plasma membrane (PM) under blue light excitation, and in the dark, it releases back to the cytoplasm. However, the molecular mechanism of optical regulation and lipid recognition is still unclear. Here using nuclear magnetic resonance (NMR) spectroscopy, liposome pulldown assay, and surface plasmon resonance (SPR), we find that OptoPB binds to membrane mimetics containing di- or triphosphorylated phosphatidylinositols, particularly phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2), an acidic phospholipid predominantly located in the eukaryotic PM. In the dark, steric hindrance prevented this protein-membrane interaction, while 470 nm blue light illumination activated it. NMR titration and site-directed mutagenesis revealed that both cationic and hydrophobic Rit-PB residues are essential to the membrane interaction, indicating that OptoPB binds the membrane via a specific PI(4,5)P2-dependent mechanism.
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Affiliation(s)
- Ling Li
- High Magnetic Field Laboratory, CAS Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China
- University of Science and Technology of China, Hefei 230026, China
| | - Lian He
- Center for Translational Cancer Research, Institute of Biosciences and Technology, Texas A&M University, Houston, Texas 77030, United States
| | - Bo Wu
- High Magnetic Field Laboratory, CAS Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China
| | - Chuandi Yu
- High Magnetic Field Laboratory, CAS Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China
- University of Science and Technology of China, Hefei 230026, China
| | - Hongxin Zhao
- High Magnetic Field Laboratory, CAS Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China
| | - Yubin Zhou
- Center for Translational Cancer Research, Institute of Biosciences and Technology, Texas A&M University, Houston, Texas 77030, United States
| | - Junfeng Wang
- High Magnetic Field Laboratory, CAS Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China
- University of Science and Technology of China, Hefei 230026, China
- Institute of Physical Science and Information Technology, Anhui University, Hefei 230031, China
| | - Lei Zhu
- High Magnetic Field Laboratory, CAS Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China
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