1
|
Shafaei Pishabad Z, Ledgerwood EC. The Y49H cytochrome c variant enhances megakaryocytic maturation of K-562 cells. Biochim Biophys Acta Mol Basis Dis 2024; 1870:167134. [PMID: 38531481 DOI: 10.1016/j.bbadis.2024.167134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 02/22/2024] [Accepted: 03/18/2024] [Indexed: 03/28/2024]
Abstract
Five pathogenic variants in the gene encoding cytochrome c (CYCS) associated with mild autosomal dominant thrombocytopenia have been reported. Previous studies of peripheral blood CD34+ or CD45+ cells from subjects with the G42S CYCS variant showed an acceleration in megakaryopoiesis compared to wild-type (WT) cells. To determine whether this result reflects a common feature of the CYCS variants, the c.145T>C mutation (Y49H variant) was introduced into the endogenous CYCS locus in K-562 cells, which undergo megakaryocytic maturation in response to treatment with a phorbol ester. The c.145T>C (Y49H) variant enhanced the megakaryocyte maturation of the K-562 cells, and this effect was seen when the cells were cultured at both 18 % and 5 % oxygen. Thus, alteration of megakaryopoiesis is common to both the G42S and Y49H CYCS variants and may contribute to the low platelet phenotype. The Y49H CYCS variant has previously been reported to impair mitochondrial respiratory chain function in vitro, however using extracellular flux analysis the c.145T>C (Y49H) variant does not alter mitochondrial bioenergetics of the K-562 cells, consistent with the lack of a phenotype characteristic of mitochondrial diseases in CYCS variant families. The Y49H variant has also been reported to enhance the ability of cytochrome c to trigger caspase activation in the intrinsic apoptosis pathway. However, as seen in peripheral blood cells from G42S CYCS variant carriers, the presence of Y49H cytochrome c in K-562 cells did not significantly change their response to an apoptotic stimulus.
Collapse
Affiliation(s)
- Zahra Shafaei Pishabad
- Department of Biochemistry, School of Biomedical Sciences, University of Otago, PO Box 56, Dunedin 9054, New Zealand
| | - Elizabeth C Ledgerwood
- Department of Biochemistry, School of Biomedical Sciences, University of Otago, PO Box 56, Dunedin 9054, New Zealand.
| |
Collapse
|
2
|
Chin TC, Wilbanks SM, Ledgerwood EC. Altered conformational dynamics contribute to species-specific effects of cytochrome c mutations on caspase activation. J Biol Inorg Chem 2024; 29:169-176. [PMID: 38472487 PMCID: PMC11098916 DOI: 10.1007/s00775-024-02044-2] [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: 07/27/2023] [Accepted: 01/08/2024] [Indexed: 03/14/2024]
Abstract
Variants in the gene encoding human cytochrome c (CYCS) cause mild autosomal dominant thrombocytopenia. Despite high sequence conservation between mouse and human cytochrome c, this phenotype is not recapitulated in mice for the sole mutant (G41S) that has been investigated. The effect of the G41S mutation on the in vitro activities of cytochrome c is also not conserved between human and mouse. Peroxidase activity is increased in both mouse and human G41S variants, whereas apoptosome activation is increased for human G41S cytochrome c but decreased for mouse G41S cytochrome c. These apoptotic activities of cytochrome c are regulated at least in part by conformational dynamics of the main chain. Here we use computational and in vitro approaches to understand why the impact of the G41S mutation differs between mouse and human cytochromes c. The G41S mutation increases the inherent entropy and main chain mobility of human but not mouse cytochrome c. Exclusively in human G41S cytochrome c this is accompanied by a decrease in occupancy of H-bonds between protein and heme during simulations. These data demonstrate that binding of cytochrome c to Apaf-1 to trigger apoptosome formation, but not the peroxidase activity of cytochrome c, is enhanced by increased mobility of the native protein conformation.
Collapse
Affiliation(s)
- Thomas C Chin
- Biochemistry Department, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Sigurd M Wilbanks
- Biochemistry Department, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Elizabeth C Ledgerwood
- Biochemistry Department, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand.
| |
Collapse
|
3
|
Semenova MA, Chertkova RV, Kirpichnikov MP, Dolgikh DA. Molecular Interactions between Neuroglobin and Cytochrome c: Possible Mechanisms of Antiapoptotic Defense in Neuronal Cells. Biomolecules 2023; 13:1233. [PMID: 37627298 PMCID: PMC10452090 DOI: 10.3390/biom13081233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Revised: 08/06/2023] [Accepted: 08/08/2023] [Indexed: 08/27/2023] Open
Abstract
Neuroglobin, which is a heme protein from the globin family that is predominantly expressed in nervous tissue, can promote a neuronal survivor. However, the molecular mechanisms underlying the neuroprotective function of Ngb remain poorly understood to this day. The interactions between neuroglobin and mitochondrial cytochrome c may serve as at least one of the mechanisms of neuroglobin-mediated neuroprotection. Interestingly, neuroglobin and cytochrome c possibly can interact with or without electron transfer both in the cytoplasm and within the mitochondria. This review provides a general picture of molecular interactions between neuroglobin and cytochrome c based on the recent experimental and computational work on neuroglobin and cytochrome c interactions.
Collapse
Affiliation(s)
- Marina A. Semenova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho–Maklaya St. 16/10, 117997 Moscow, Russia
| | - Rita V. Chertkova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho–Maklaya St. 16/10, 117997 Moscow, Russia
| | - Mikhail P. Kirpichnikov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho–Maklaya St. 16/10, 117997 Moscow, Russia
- Biology Department, Lomonosov Moscow State University, Leninskie Gory, 119899 Moscow, Russia
| | - Dmitry A. Dolgikh
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho–Maklaya St. 16/10, 117997 Moscow, Russia
- Biology Department, Lomonosov Moscow State University, Leninskie Gory, 119899 Moscow, Russia
| |
Collapse
|
4
|
Altered structure and dynamics of pathogenic cytochrome c variants correlate with increased apoptotic activity. Biochem J 2021; 478:669-684. [PMID: 33480393 DOI: 10.1042/bcj20200793] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2020] [Revised: 01/17/2021] [Accepted: 01/21/2021] [Indexed: 01/16/2023]
Abstract
Mutation of cytochrome c in humans causes mild autosomal dominant thrombocytopenia. The role of cytochrome c in platelet formation, and the molecular mechanism underlying the association of cytochrome c mutations with thrombocytopenia remains unknown, although a gain-of-function is most likely. Cytochrome c contributes to several cellular processes, with an exchange between conformational states proposed to regulate changes in function. Here, we use experimental and computational approaches to determine whether pathogenic variants share changes in structure and function, and to understand how these changes might occur. Three pathogenic variants (G41S, Y48H, A51V) cause an increase in apoptosome activation and peroxidase activity. Molecular dynamics simulations of these variants, and two non-naturally occurring variants (G41A, G41T), indicate that increased apoptosome activation correlates with the increased overall flexibility of cytochrome c, particularly movement of the Ω loops. Crystal structures of Y48H and G41T complement these studies which overall suggest that the binding of cytochrome c to apoptotic protease activating factor-1 (Apaf-1) may involve an 'induced fit' mechanism which is enhanced in the more conformationally mobile variants. In contrast, peroxidase activity did not significantly correlate with protein dynamics. Thus, the mechanism by which the variants increase peroxidase activity is not related to the conformational dynamics of the native hexacoordinate state of cytochrome c. Recent molecular dynamics data proposing conformational mobility of specific cytochrome c regions underpins changes in reduction potential and alkaline transition pK was not fully supported. These data highlight that conformational dynamics of cytochrome c drive some but not all of its properties and activities.
Collapse
|
5
|
Ledgerwood EC, Dunstan-Harrison C, Ong L, Morison IM. CYCS gene variants associated with thrombocytopenia. Platelets 2018; 30:672-674. [PMID: 30452302 DOI: 10.1080/09537104.2018.1543866] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Elizabeth C Ledgerwood
- a Department of Biochemistry, School of Biomedical Sciences , University of Otago , Dunedin , New Zealand
| | - Caitlin Dunstan-Harrison
- a Department of Biochemistry, School of Biomedical Sciences , University of Otago , Dunedin , New Zealand
| | - Lily Ong
- a Department of Biochemistry, School of Biomedical Sciences , University of Otago , Dunedin , New Zealand
| | - Ian M Morison
- b Department of Pathology, Dunedin School of Medicine , University of Otago , Dunedin , New Zealand
| |
Collapse
|
6
|
Alvarez-Paggi D, Hannibal L, Castro MA, Oviedo-Rouco S, Demicheli V, Tórtora V, Tomasina F, Radi R, Murgida DH. Multifunctional Cytochrome c: Learning New Tricks from an Old Dog. Chem Rev 2017; 117:13382-13460. [DOI: 10.1021/acs.chemrev.7b00257] [Citation(s) in RCA: 135] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Damián Alvarez-Paggi
- Departamento
de Química Inorgánica, Analítica y Química
Física and INQUIMAE (CONICET-UBA), Facultad de Ciencias Exactas
y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pab. 2, piso 1, Buenos Aires C1428EHA, Argentina
| | - Luciana Hannibal
- Department
of Pediatrics, Universitätsklinikum Freiburg, Mathildenstrasse 1, Freiburg 79106, Germany
- Departamento
de Bioquímica and Center for Free Radical and Biomedical Research,
Facultad de Medicina, Universidad de la República, Av.
Gral. Flores 2125, Montevideo 11800, Uruguay
| | - María A. Castro
- Departamento
de Química Inorgánica, Analítica y Química
Física and INQUIMAE (CONICET-UBA), Facultad de Ciencias Exactas
y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pab. 2, piso 1, Buenos Aires C1428EHA, Argentina
| | - Santiago Oviedo-Rouco
- Departamento
de Química Inorgánica, Analítica y Química
Física and INQUIMAE (CONICET-UBA), Facultad de Ciencias Exactas
y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pab. 2, piso 1, Buenos Aires C1428EHA, Argentina
| | - Veronica Demicheli
- Departamento
de Bioquímica and Center for Free Radical and Biomedical Research,
Facultad de Medicina, Universidad de la República, Av.
Gral. Flores 2125, Montevideo 11800, Uruguay
| | - Veronica Tórtora
- Departamento
de Bioquímica and Center for Free Radical and Biomedical Research,
Facultad de Medicina, Universidad de la República, Av.
Gral. Flores 2125, Montevideo 11800, Uruguay
| | - Florencia Tomasina
- Departamento
de Bioquímica and Center for Free Radical and Biomedical Research,
Facultad de Medicina, Universidad de la República, Av.
Gral. Flores 2125, Montevideo 11800, Uruguay
| | - Rafael Radi
- Departamento
de Bioquímica and Center for Free Radical and Biomedical Research,
Facultad de Medicina, Universidad de la República, Av.
Gral. Flores 2125, Montevideo 11800, Uruguay
| | - Daniel H. Murgida
- Departamento
de Química Inorgánica, Analítica y Química
Física and INQUIMAE (CONICET-UBA), Facultad de Ciencias Exactas
y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pab. 2, piso 1, Buenos Aires C1428EHA, Argentina
| |
Collapse
|
7
|
Karsisiotis AI, Deacon OM, Wilson MT, Macdonald C, Blumenschein TMA, Moore GR, Worrall JAR. Increased dynamics in the 40-57 Ω-loop of the G41S variant of human cytochrome c promote its pro-apoptotic conformation. Sci Rep 2016; 6:30447. [PMID: 27461282 PMCID: PMC4962053 DOI: 10.1038/srep30447] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Accepted: 07/05/2016] [Indexed: 12/26/2022] Open
Abstract
Thrombocytopenia 4 is an inherited autosomal dominant thrombocytopenia, which occurs due to mutations in the human gene for cytochrome c that results in enhanced mitochondrial apoptotic activity. The Gly41Ser mutation was the first to be reported. Here we report stopped-flow kinetic studies of azide binding to human ferricytochrome c and its Gly41Ser variant, together with backbone amide H/D exchange and 15N-relaxation dynamics using NMR spectroscopy, to show that alternative conformations are kinetically and thermodynamically more readily accessible for the Gly41Ser variant than for the wild-type protein. Our work reveals a direct conformational link between the 40–57 Ω-loop in which residue 41 resides and the dynamical properties of the axial ligand to the heme iron, Met80, such that the replacement of glycine by serine promotes the dissociation of the Met80 ligand, thereby increasing the population of a peroxidase active state, which is a key non-native conformational state in apoptosis.
Collapse
Affiliation(s)
| | - Oliver M Deacon
- School of Biological Sciences, University of Essex, Wivenhoe Park, Colchester, CO4 3SQ, UK
| | - Michael T Wilson
- School of Biological Sciences, University of Essex, Wivenhoe Park, Colchester, CO4 3SQ, UK
| | - Colin Macdonald
- School of Chemistry, University of East Anglia, Norwich Research Park, NR4 7TJ, UK
| | | | - Geoffrey R Moore
- School of Chemistry, University of East Anglia, Norwich Research Park, NR4 7TJ, UK
| | - Jonathan A R Worrall
- School of Biological Sciences, University of Essex, Wivenhoe Park, Colchester, CO4 3SQ, UK
| |
Collapse
|