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Sprenger J, Trifan A, Patel N, Vanderbeck A, Bredfelt J, Tajkhorshid E, Rowlett R, Lo Leggio L, Åkerfeldt KS, Linse S. Calmodulin complexes with brain and muscle creatine kinase peptides. Curr Res Struct Biol 2021; 3:121-132. [PMID: 34235492 PMCID: PMC8244255 DOI: 10.1016/j.crstbi.2021.05.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Revised: 04/27/2021] [Accepted: 05/03/2021] [Indexed: 01/18/2023] Open
Abstract
Calmodulin (CaM) is a ubiquitous Ca2+ sensing protein that binds to and modulates numerous target proteins and enzymes during cellular signaling processes. A large number of CaM-target complexes have been identified and structurally characterized, revealing a wide diversity of CaM-binding modes. A newly identified target is creatine kinase (CK), a central enzyme in cellular energy homeostasis. This study reports two high-resolution X-ray structures, determined to 1.24 Å and 1.43 Å resolution, of calmodulin in complex with peptides from human brain and muscle CK, respectively. Both complexes adopt a rare extended binding mode with an observed stoichiometry of 1:2 CaM:peptide, confirmed by isothermal titration calorimetry, suggesting that each CaM domain independently binds one CK peptide in a Ca2+-depended manner. While the overall binding mode is similar between the structures with muscle or brain-type CK peptides, the most significant difference is the opposite binding orientation of the peptides in the N-terminal domain. This may extrapolate into distinct binding modes and regulation of the full-length CK isoforms. The structural insights gained in this study strengthen the link between cellular energy homeostasis and Ca2+-mediated cell signaling and may shed light on ways by which cells can 'fine tune' their energy levels to match the spatial and temporal demands.
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Key Words
- ADP, Adenosine diphosphate
- ATP, Adenosine triphosphate
- CK, Creatine kinase
- CKB, Creatine kinase, brain-type
- CKM, Creatine kinase, muscle-type
- Ca2+, Calcium ion (divalent)
- CaM, Calmodulin
- Calcium signaling
- Calmodulin X-ray structure
- Cellular energy metabolism
- Cr, Creatine
- CrP, Creatine phosphate
- Enzyme regulation
- Fmoc, Fluorenylmethoxycarbonyl
- ITC, Isothermal titration calorimetry
- Isothermal titration calorimetry
- MR, Molecular replacement
- PDB, Protein data bank
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Affiliation(s)
- Janina Sprenger
- Department of Biochemistry and Structural Biology, Chemical Center, PO Box 124, SE-221 00, Lund, Sweden
- Chemistry Department, University of Copenhagen, Universitetsparken 5, 2100, Copenhagen, Denmark
| | - Anda Trifan
- Theoretical and Computational Biophysics Group, NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology, Department of Biochemistry, and Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, 405 N Matthews, Urbana, IL, 61801, USA
| | - Neal Patel
- Department of Chemistry, Haverford College, 370 Lancaster Avenue, Haverford, PA, 19041, USA
| | - Ashley Vanderbeck
- Department of Chemistry, Haverford College, 370 Lancaster Avenue, Haverford, PA, 19041, USA
| | - Jenny Bredfelt
- Department of Biochemistry and Structural Biology, Chemical Center, PO Box 124, SE-221 00, Lund, Sweden
| | - Emad Tajkhorshid
- Theoretical and Computational Biophysics Group, NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology, Department of Biochemistry, and Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, 405 N Matthews, Urbana, IL, 61801, USA
| | - Roger Rowlett
- Department of Chemistry, Colgate University, 13 Oak Drive, Hamilton, NY, 13346, USA
| | - Leila Lo Leggio
- Chemistry Department, University of Copenhagen, Universitetsparken 5, 2100, Copenhagen, Denmark
| | - Karin S. Åkerfeldt
- Department of Chemistry, Haverford College, 370 Lancaster Avenue, Haverford, PA, 19041, USA
| | - Sara Linse
- Department of Biochemistry and Structural Biology, Chemical Center, PO Box 124, SE-221 00, Lund, Sweden
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