1
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Heath SG, Gray SG, Hamzah EM, O'Connor KM, Bozonet SM, Botha AD, de Cordovez P, Magon NJ, Naughton JD, Goldsmith DLW, Schwartfeger AJ, Sunde M, Buell AK, Morris VK, Göbl C. Amyloid formation and depolymerization of tumor suppressor p16 INK4a are regulated by a thiol-dependent redox mechanism. Nat Commun 2024; 15:5535. [PMID: 38951545 PMCID: PMC11217399 DOI: 10.1038/s41467-024-49581-7] [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: 03/16/2023] [Accepted: 06/12/2024] [Indexed: 07/03/2024] Open
Abstract
The conversion of a soluble protein into polymeric amyloid structures is a process that is poorly understood. Here, we describe a fully redox-regulated amyloid system in which cysteine oxidation of the tumor suppressor protein p16INK4a leads to rapid amyloid formation. We identify a partially-structured disulfide-bonded dimeric intermediate species that subsequently assembles into fibrils. The stable amyloid structures disassemble when the disulfide bond is reduced. p16INK4a is frequently mutated in cancers and is considered highly vulnerable to single-point mutations. We find that multiple cancer-related mutations show increased amyloid formation propensity whereas mutations stabilizing the fold prevent transition into amyloid. The complex transition into amyloids and their structural stability is therefore strictly governed by redox reactions and a single regulatory disulfide bond.
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Affiliation(s)
- Sarah G Heath
- Mātai Hāora - Centre for Redox Biology and Medicine, Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand
| | - Shelby G Gray
- School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
| | - Emilie M Hamzah
- School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
| | - Karina M O'Connor
- Mātai Hāora - Centre for Redox Biology and Medicine, Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand
| | - Stephanie M Bozonet
- Mātai Hāora - Centre for Redox Biology and Medicine, Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand
| | - Alex D Botha
- Mātai Hāora - Centre for Redox Biology and Medicine, Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand
| | - Pierre de Cordovez
- Mātai Hāora - Centre for Redox Biology and Medicine, Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand
| | - Nicholas J Magon
- Mātai Hāora - Centre for Redox Biology and Medicine, Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand
| | - Jennifer D Naughton
- Mātai Hāora - Centre for Redox Biology and Medicine, Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand
| | - Dylan L W Goldsmith
- School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
| | | | - Margaret Sunde
- School of Medical Sciences and Sydney Nano, The University of Sydney, Sydney, Australia
| | - Alexander K Buell
- Department of Biotechnology and Biomedicine, Technical University of Denmark, 2800, Lyngby, Denmark
| | - Vanessa K Morris
- School of Biological Sciences, University of Canterbury, Christchurch, New Zealand.
- Biomolecular Interaction Centre, University of Canterbury, Christchurch, New Zealand.
| | - Christoph Göbl
- Mātai Hāora - Centre for Redox Biology and Medicine, Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand.
- Biomolecular Interaction Centre, University of Canterbury, Christchurch, New Zealand.
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2
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Alam MNU. Computational assessment of somatic and germline mutations of p16INK4a: Structural insights and implications in disease. INFORMATICS IN MEDICINE UNLOCKED 2019. [DOI: 10.1016/j.imu.2019.100208] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
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3
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A method for rapid high-throughput biophysical analysis of proteins. Sci Rep 2017; 7:9071. [PMID: 28831058 PMCID: PMC5567296 DOI: 10.1038/s41598-017-08664-w] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 07/14/2017] [Indexed: 11/09/2022] Open
Abstract
Quantitative determination of protein thermodynamic stability is fundamental to many research areas, both basic and applied. Although chemical-induced denaturation is the gold-standard method, it has been replaced in many settings by semi-quantitative approaches such as thermal stability measurements. The reason for this shift is that chemical denaturation experiments are labour-intensive, sample-costly and time-consuming, and it has been assumed that miniaturisation to a high-throughput format would not be possible without concomitantly comprising data quality. Here we exploit current technologies to create a high-throughput label-free chemical denaturation method that is capable of generating replicate datasets on multiple proteins in parallel on a timescale that is at least ten times faster, much more economical on sample, and with the potential for superior data quality, than the conventional methods used in most research labs currently.
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4
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Blackburn PR, Tischer A, Zimmermann MT, Kemppainen JL, Sastry S, Knight Johnson AE, Cousin MA, Boczek NJ, Oliver G, Misra VK, Gavrilova RH, Lomberk G, Auton M, Urrutia R, Klee EW. A Novel Kleefstra Syndrome-associated Variant That Affects the Conserved TPL X Motif within the Ankyrin Repeat of EHMT1 Leads to Abnormal Protein Folding. J Biol Chem 2017; 292:3866-3876. [PMID: 28057753 PMCID: PMC5339767 DOI: 10.1074/jbc.m116.770545] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Revised: 01/05/2017] [Indexed: 12/26/2022] Open
Abstract
Kleefstra syndrome (KS) (Mendelian Inheritance in Man (MIM) no. 610253), also known as 9q34 deletion syndrome, is an autosomal dominant disorder caused by haploinsufficiency of euchromatic histone methyltransferase-1 (EHMT1). The clinical phenotype of KS includes moderate to severe intellectual disability with absent speech, hypotonia, brachycephaly, congenital heart defects, and dysmorphic facial features with hypertelorism, synophrys, macroglossia, protruding tongue, and prognathism. Only a few cases of de novo missense mutations in EHMT1 giving rise to KS have been described. However, some EHMT1 variants have been described in individuals presenting with autism spectrum disorder or mild intellectual disability, suggesting that the phenotypic spectrum resulting from EHMT1 alterations may be quite broad. In this report, we describe two unrelated patients with complex medical histories consistent with KS in whom next generation sequencing identified the same novel c.2426C>T (p.P809L) missense variant in EHMT1. To examine the functional significance of this novel variant, we performed molecular dynamics simulations of the wild type and p.P809L variant, which predicted that the latter would have a propensity to misfold, leading to abnormal histone mark binding. Recombinant EHMT1 p.P809L was also studied using far UV circular dichroism spectroscopy and intrinsic protein fluorescence. These functional studies confirmed the model-based hypotheses and provided evidence for protein misfolding and aberrant target recognition as the underlying pathogenic mechanism for this novel KS-associated variant. This is the first report to suggest that missense variants in EHMT1 that lead to protein misfolding and disrupted histone mark binding can lead to KS.
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Affiliation(s)
- Patrick R Blackburn
- From the Center for Individualized Medicine and.,the Department of Health Science Research, Mayo Clinic, Jacksonville, Florida 32224
| | - Alexander Tischer
- the Division of Hematology, Departments of Internal Medicine and Biochemistry and Molecular Biology
| | - Michael T Zimmermann
- the Department of Health Science Research, Division of Biomedical Statistics and Informatics
| | | | - Sujatha Sastry
- the Department of Pediatrics, Division of Genetics and Metabolic Disorders, Wayne State University School of Medicine, Detroit, Michigan 48201, and
| | - Amy E Knight Johnson
- the Department of Human Genetics, University of Chicago, Chicago, Illinois 60637
| | - Margot A Cousin
- the Center for Individualized Medicine.,the Department of Health Science Research
| | - Nicole J Boczek
- the Center for Individualized Medicine.,the Department of Health Science Research
| | | | - Vinod K Misra
- the Department of Pediatrics, Division of Genetics and Metabolic Disorders, Wayne State University School of Medicine, Detroit, Michigan 48201, and
| | | | - Gwen Lomberk
- the Laboratory of Epigenetics and Chromatin Dynamics, Epigenomics Translational Program, Center for Individualized Medicine, Mayo Clinic, Rochester, Minnesota 55905
| | - Matthew Auton
- the Division of Hematology, Departments of Internal Medicine and Biochemistry and Molecular Biology
| | - Raul Urrutia
- the Laboratory of Epigenetics and Chromatin Dynamics, Epigenomics Translational Program, Center for Individualized Medicine, Mayo Clinic, Rochester, Minnesota 55905,
| | - Eric W Klee
- the Department of Clinical Genomics, .,the Center for Individualized Medicine.,the Department of Health Science Research
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5
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Panigrahi P, Sule M, Ghanate A, Ramasamy S, Suresh CG. Engineering Proteins for Thermostability with iRDP Web Server. PLoS One 2015; 10:e0139486. [PMID: 26436543 PMCID: PMC4593602 DOI: 10.1371/journal.pone.0139486] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Accepted: 09/13/2015] [Indexed: 11/18/2022] Open
Abstract
Engineering protein molecules with desired structure and biological functions has been an elusive goal. Development of industrially viable proteins with improved properties such as stability, catalytic activity and altered specificity by modifying the structure of an existing protein has widely been targeted through rational protein engineering. Although a range of factors contributing to thermal stability have been identified and widely researched, the in silico implementation of these as strategies directed towards enhancement of protein stability has not yet been explored extensively. A wide range of structural analysis tools is currently available for in silico protein engineering. However these tools concentrate on only a limited number of factors or individual protein structures, resulting in cumbersome and time-consuming analysis. The iRDP web server presented here provides a unified platform comprising of iCAPS, iStability and iMutants modules. Each module addresses different facets of effective rational engineering of proteins aiming towards enhanced stability. While iCAPS aids in selection of target protein based on factors contributing to structural stability, iStability uniquely offers in silico implementation of known thermostabilization strategies in proteins for identification and stability prediction of potential stabilizing mutation sites. iMutants aims to assess mutants based on changes in local interaction network and degree of residue conservation at the mutation sites. Each module was validated using an extensively diverse dataset. The server is freely accessible at http://irdp.ncl.res.in and has no login requirements.
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Affiliation(s)
- Priyabrata Panigrahi
- Division of Biochemical Sciences, CSIR-National Chemical Laboratory, Pune, Maharashtra, 411008, India
| | - Manas Sule
- Division of Biochemical Sciences, CSIR-National Chemical Laboratory, Pune, Maharashtra, 411008, India
| | - Avinash Ghanate
- Division of Chemical Engineering and Process Development, CSIR-National Chemical Laboratory, Pune, Maharashtra, 411008, India
| | - Sureshkumar Ramasamy
- Division of Biochemical Sciences, CSIR-National Chemical Laboratory, Pune, Maharashtra, 411008, India
| | - C. G. Suresh
- Division of Biochemical Sciences, CSIR-National Chemical Laboratory, Pune, Maharashtra, 411008, India
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6
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Guo Y, Yuan C, Tian F, Huang K, Weghorst CM, Tsai MD, Li J. Contributions of conserved TPLH tetrapeptides to the conformational stability of ankyrin repeat proteins. J Mol Biol 2010; 399:168-81. [PMID: 20398677 DOI: 10.1016/j.jmb.2010.04.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2009] [Revised: 03/27/2010] [Accepted: 04/06/2010] [Indexed: 01/11/2023]
Abstract
Ankyrin repeat (AR) proteins are one of the most abundant classes of repeat proteins and are involved in numerous physiological processes. These proteins are composed of various numbers of AR motifs stacked in a nearly linear fashion to adopt an elongated and nonglobular architecture. One salient feature prevalent in such a structural unit is the TPLH tetrapeptide or a close variant, T/SxxH, which initiates the helix-turn-helix conformation and presumably contributes to conformational stability through a hydrogen-bonding network. In the present study, we investigated the roles of T/SxxH motif in the stability, structure, and function of AR proteins by a systematic and rationalized mutagenic study on, followed by biochemical and biophysical characterization of, gankyrin, an oncogenic protein composed of seven ARs and six T/SxxH tetrapeptides, and P16, a tumor suppressor with four ARs but no TPLH tetrapeptide. Our results showed that this tetrapeptide is ineffectual on global structure and function, but contributes significantly to conformational stability when its stabilizing potentials are fully realized in the local conformation, including (1) the intra-AR hydrogen bonding involving the hydroxyl group; (2) the intra-AR and inter-AR hydrogen bonds involving the imidazole ring; and (3) the hydrophobic interaction associated with the Thr-methyl group. Considering that the capping and close-to-capping units tend to have more sequence diversity and more conformational variation, it could be also generally true that a T/SxxH motif close to the terminal repeats contributes little or even negatively to stability with respect to Ala substitution, but substantially stabilizes the global conformation when located in the middle of a long stretch of ARs.
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Affiliation(s)
- Yi Guo
- Ohio State Biochemistry Program, The Ohio State University, Columbus, OH 43210, USA
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7
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Guo Y, Mahajan A, Yuan C, Joo SH, Weghorst CM, Tsai MD, Li J. Comparisons of the conformational stability of cyclin-dependent kinase (CDK) 4-interacting ankyrin repeat (AR) proteins. Biochemistry 2009; 48:4050-62. [PMID: 19320462 DOI: 10.1021/bi802247p] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Ankyrin repeat (AR) proteins are one of the most abundant repeat protein classes in nature, and they are involved in numerous physiological processes through mediating protein/protein interactions. The repetitive and modular architecture of these AR proteins may lead to biochemical and biophysical properties distinct from those of globular proteins. It has been demonstrated that like most globular proteins, AR proteins exhibit a two-state, cooperative transition in chemical- and heat-induced unfolding. However, the biophysical characteristics underlying such cooperative unfolding remain to be further investigated. In the present study, we evaluated the conformational stability of a group of cyclin-dependent kinase (CDK) 4-interacting AR proteins, P16, P18, IkappaBalpha, gankyrin, and their truncated mutants under different conditions, including the presence of denaturants, temperature, and pH. Our results showed that the first four N-terminal ARs are required to form a potent and stable CDK4 modulator. Moreover, in spite of their similarities in skeleton structure, CDK4 binding, and cooperative unfolding, P16, P18, IkappaBalpha, and gankyrin exhibited considerably different biophysical properties with regard to the conformational stability, and these differences mainly resulted from the discrepancies in the primary sequence of the relatively conserved AR motifs. Our results also demonstrated that these sequence discrepancies are able to influence the function of AR proteins to a certain extent. Overall, our results provide important insights into understanding the biophysical properties of AR proteins.
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Affiliation(s)
- Yi Guo
- Ohio State Biochemistry Program, The Ohio State University, Columbus, Ohio 43210, USA
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8
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McKenzie H, Becker TM, Scurr LL, Kefford RF, Rizos H. Wild type and melanoma-associated mutant p16(IN4a) proteins do not oligomerize in vivo. Pigment Cell Melanoma Res 2009; 22:131-3. [PMID: 19154236 DOI: 10.1111/j.1755-148x.2008.00530.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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9
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Kelly L, McDonough MA, Coleman ML, Ratcliffe PJ, Schofield CJ. Asparagine β-hydroxylation stabilizes the ankyrin repeat domain fold. ACTA ACUST UNITED AC 2009; 5:52-8. [DOI: 10.1039/b815271c] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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10
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Li J, Mahajan A, Tsai MD. Ankyrin repeat: a unique motif mediating protein-protein interactions. Biochemistry 2008; 45:15168-78. [PMID: 17176038 DOI: 10.1021/bi062188q] [Citation(s) in RCA: 441] [Impact Index Per Article: 27.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Ankyrin repeat, one of the most widely existing protein motifs in nature, consists of 30-34 amino acid residues and exclusively functions to mediate protein-protein interactions, some of which are directly involved in the development of human cancer and other diseases. Each ankyrin repeat exhibits a helix-turn-helix conformation, and strings of such tandem repeats are packed in a nearly linear array to form helix-turn-helix bundles with relatively flexible loops. The global structure of an ankyrin repeat protein is mainly stabilized by intra- and inter-repeat hydrophobic and hydrogen bonding interactions. The repetitive and elongated nature of ankyrin repeat proteins provides the molecular bases of the unique characteristics of ankyrin repeat proteins in protein stability, folding and unfolding, and binding specificity. Recent studies have demonstrated that ankyrin repeat proteins do not recognize specific sequences, and interacting residues are discontinuously dispersed into the whole molecules of both the ankyrin repeat protein and its partner. In addition, the availability of thousands of ankyrin repeat sequences has made it feasible to use rational design to modify the specificity and stability of physiologically important ankyrin repeat proteins and even to generate ankyrin repeat proteins with novel functions through combinatorial chemistry approaches.
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Affiliation(s)
- Junan Li
- Department of Chemistry, The Ohio State University, Columbus, Ohio 43210, USA.
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11
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Charbonnier S, Gallego O, Gavin AC. The social network of a cell: recent advances in interactome mapping. BIOTECHNOLOGY ANNUAL REVIEW 2008; 14:1-28. [PMID: 18606358 DOI: 10.1016/s1387-2656(08)00001-x] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Proteins very rarely act in isolation. Biomolecular interactions are central to all biological functions. In human, for example, interference with biomolecular networks often lead to disease. Protein-protein and protein-metabolite interactions have traditionally been studied one by one. Recently, significant progresses have been made in adapting suitable tools for the global analysis of biomolecular interactions. Here we review this suite of powerful technologies that enable an exponentially growing number of large-scale interaction datasets. These new technologies have already contributed to a more comprehensive cartography of several pathways relevant to human pathologies, offering a broader choice for therapeutic targets. Genome-wide scale analyses in model organisms reveal general organizational principles of eukaryotic proteomes. We also review the biochemical approaches that have been used in the past on a smaller scale for the quantification of the binding constant and the thermodynamics parameters governing biomolecular interaction. The adaptation of these technologies to the large-scale measurement of biomolecular interactions in (semi-)quantitative terms represents an important challenge.
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Affiliation(s)
- Sebastian Charbonnier
- EMBL, Structural and Computational Biology Unit, Meyerhofstrasse 1, D-69117 Heidelberg, Germany
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12
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Borzok MA, Catino DH, Nicholson JD, Kontrogianni-Konstantopoulos A, Bloch RJ. Mapping the binding site on small ankyrin 1 for obscurin. J Biol Chem 2007; 282:32384-96. [PMID: 17720975 DOI: 10.1074/jbc.m704089200] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Small ankyrin 1 (sAnk1), an integral protein of the sarcoplasmic reticulum encoded by the ANK1 gene, binds with nanomolar affinity to the C terminus of obscurin, a giant protein surrounding the contractile apparatus in striated muscle. We used site-directed mutagenesis to characterize the binding site on sAnk1, specifically addressing the role of two putative amphipathic, positively charged helices. We measured binding qualitatively by blot overlay assays and quantitatively by surface plasmon resonance and showed that both positively charged sequences are required for activity. We showed further that substitution of a lysine or arginine with an alanine or glutamate located at the same position along either of the two putative helices has similar inhibitory or stimulatory effects on binding and that the effects of a particular mutation depended on the position of the mutated amino acid in each helix. We modeled the structure of the binding region of sAnk1 by homology with ankyrin repeats of human Notch1, which have a similar pattern of charged and hydrophobic residues. Our modeling suggested that each of the two positively charged sequences forms pairs of amphipathic, anti-parallel alpha-helices flanked by beta-hairpin-like turns. Most of the residues in homologous positions along each helical unit have similar, though not identical, orientations. CD spectroscopy confirmed the alpha-helical content of sAnk1, approximately 33%, predicted by the model. Thus, structural and mutational studies of the binding region on sAnk1 for obscurin suggest that it consists of two ankyrin repeats with very similar structures.
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Affiliation(s)
- Maegen A Borzok
- Department of Biochemistry and Molecular Biology, University of Maryland, School of Medicine, Baltimore 21201, USA
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13
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Desrosiers DC, Peng ZY. A Binding Free Energy Hot Spot in the Ankyrin Repeat Protein GABPβ Mediated Protein–Protein Interaction. J Mol Biol 2005; 354:375-84. [PMID: 16243355 DOI: 10.1016/j.jmb.2005.09.045] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2005] [Revised: 09/07/2005] [Accepted: 09/16/2005] [Indexed: 11/17/2022]
Abstract
The frequently observed ankyrin repeat motif represents a structural scaffold evolved for mediating protein-protein interactions. As such, these repeats modulate a diverse range of cellular functions. We thermodynamically characterized the heterodimeric GA-binding protein (GABP) alphabeta complex and focused specifically on the interaction mediated by the ankyrin repeat domain of the GABPbeta. Our isothermal titration calorimetric analysis of the interaction between the GABP subunits determined an association constant (K(A)) of 6.0 x 10(8) M(-1) and that the association is favorably driven by a significant change in enthalpy (DeltaH) and a minor change in entropy (-TDeltaS). A total of 16 GABPbeta interface residues were chosen for alanine scanning mutagenesis. The calorimetrically measured differences in the free energy of binding were compared to computationally calculated values resulting in a correlation coefficient r = 0.71. We identified three spatially contiguous hydrophobic and aromatic residues that form a binding free energy hot spot (DeltaDeltaG > 2.0 kcal/mol). One residue provides structural support to the hot spot residues. Three non-hot spot residues are intermediate contributors (DeltaDeltaG approximately 1.0 kcal/mol) and create a canopy-like structure over the hot spot residues to possibly occlude solvent and orientate the subunits. The remaining interface residues are located peripherally and have weak contributions. Finally, our mutational analysis revealed a significant entropy-enthalpy compensation for this interaction.
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Affiliation(s)
- Daniel C Desrosiers
- Department of Molecular, Microbial and Structural Biology, University of Connecticut Health Center, Farmington, CT 06032, USA.
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14
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Lubman OY, Kopan R, Waksman G, Korolev S. The crystal structure of a partial mouse Notch-1 ankyrin domain: repeats 4 through 7 preserve an ankyrin fold. Protein Sci 2005; 14:1274-81. [PMID: 15802643 PMCID: PMC2253258 DOI: 10.1110/ps.041184105] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Folding and stability of proteins containing ankyrin repeats (ARs) is of great interest because they mediate numerous protein-protein interactions involved in a wide range of regulatory cellular processes. Notch, an ankyrin domain containing protein, signals by converting a transcriptional repression complex into an activation complex. The Notch ANK domain is essential for Notch function and contains seven ARs. Here, we present the 2.2 A crystal structure of ARs 4-7 from mouse Notch 1 (m1ANK). These C-terminal repeats were resistant to degradation during crystallization, and their secondary and tertiary structures are maintained in the absence of repeats 1-3. The crystallized fragment adopts a typical ankyrin fold including the poorly conserved seventh AR, as seen in the Drosophila Notch ANK domain (dANK). The structural preservation and stability of the C-terminal repeats shed a new light onto the mechanism of hetero-oligomeric assembly during Notch-mediated transcriptional activation.
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Affiliation(s)
- Olga Y Lubman
- Department of Molecular Biology and Pharmacology, Washington University School of Medicine, St. Louis, Missouri 63110, USA
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15
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Tsai HHG, Tsai CJ, Ma B, Nussinov R. In silico protein design by combinatorial assembly of protein building blocks. Protein Sci 2005; 13:2753-65. [PMID: 15388863 PMCID: PMC2286547 DOI: 10.1110/ps.04774004] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Utilizing concepts of protein building blocks, we propose a de novo computational algorithm that is similar to combinatorial shuffling experiments. Our goal is to engineer new naturally occurring folds with low homology to existing proteins. A selected protein is first partitioned into its building blocks based on their compactness, degree of isolation from the rest of the structure, and hydrophobicity. Next, the protein building blocks are substituted by fragments taken from other proteins with overall low sequence identity, but with a similar hydrophobic/hydrophilic pattern and a high structural similarity. These criteria ensure that the designed protein has a similar fold, low sequence identity, and a good hydrophobic core compared with its native counterpart. Here, we have selected two proteins for engineering, protein G B1 domain and ubiquitin. The two engineered proteins share approximately 20% and approximately 25% amino acid sequence identities with their native counterparts, respectively. The stabilities of the engineered proteins are tested by explicit water molecular dynamics simulations. The algorithm implements a strategy of designing a protein using relatively stable fragments, with a high population time. Here, we have selected the fragments by searching for local minima along the polypeptide chain using the protein building block model. Such an approach provides a new method for engineering new proteins with similar folds and low homology.
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Affiliation(s)
- Hui-Hsu Gavin Tsai
- Basic Research Program, SAIC-Frederick, Inc., Laboratory of Experimental and Computational Biology, NCI-Frederick, Building 469, Room 145, Frederick, MD 21702, USA
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16
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Mosavi LK, Cammett TJ, Desrosiers DC, Peng ZY. The ankyrin repeat as molecular architecture for protein recognition. Protein Sci 2005; 13:1435-48. [PMID: 15152081 PMCID: PMC2279977 DOI: 10.1110/ps.03554604] [Citation(s) in RCA: 636] [Impact Index Per Article: 33.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The ankyrin repeat is one of the most frequently observed amino acid motifs in protein databases. This protein-protein interaction module is involved in a diverse set of cellular functions, and consequently, defects in ankyrin repeat proteins have been found in a number of human diseases. Recent biophysical, crystallographic, and NMR studies have been used to measure the stability and define the various topological features of this motif in an effort to understand the structural basis of ankyrin repeat-mediated protein-protein interactions. Characterization of the folding and assembly pathways suggests that ankyrin repeat domains generally undergo a two-state folding transition despite their modular structure. Also, the large number of available sequences has allowed the ankyrin repeat to be used as a template for consensus-based protein design. Such projects have been successful in revealing positions responsible for structure and function in the ankyrin repeat as well as creating a potential universal scaffold for molecular recognition.
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Affiliation(s)
- Leila K Mosavi
- MC3305, Department of Molecular, Microbial, and Structural Biology, University of Connecticut Health Center, 263 Farmington Avenue, Farmington, CT 06032, USA
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17
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Abstract
Consensus design is a valuable protein-engineering method that is based on statistical information derived from sequence alignments of homologous proteins. Recently, consensus design was adapted to repeat proteins. We discuss the potential of this novel repeat-based approach for the design of consensus repeat proteins and repeat protein libraries and summarize recent results from such experiments.
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Affiliation(s)
- Patrik Forrer
- Biochemisches Institut, Universität Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland
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18
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Main ERG, Jackson SE, Regan L. The folding and design of repeat proteins: reaching a consensus. Curr Opin Struct Biol 2003; 13:482-9. [PMID: 12948778 DOI: 10.1016/s0959-440x(03)00105-2] [Citation(s) in RCA: 96] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Although they are widely distributed across kingdoms and are involved in a myriad of essential processes, until recently, repeat proteins have received little attention in comparison to globular proteins. As the name indicates, repeat proteins contain strings of tandem repeats of a basic structural element. In this respect, their construction is quite different from that of globular proteins, in which sequentially distant elements coalesce to form the protein. The different families of repeat proteins use their diverse scaffolds to present highly specific binding surfaces through which protein-protein interactions are mediated. Recent studies seek to understand the stability, folding and design of this important class of proteins.
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Affiliation(s)
- Ewan R G Main
- Department of Molecular Biophysics & Biochemistry, Yale University, 266 Whitney Avenue, New Haven, CT 06520, USA
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