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Miyazawa S. Boltzmann Machine Learning and Regularization Methods for Inferring Evolutionary Fields and Couplings From a Multiple Sequence Alignment. IEEE/ACM TRANSACTIONS ON COMPUTATIONAL BIOLOGY AND BIOINFORMATICS 2022; 19:328-342. [PMID: 32396099 DOI: 10.1109/tcbb.2020.2993232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The inverse Potts problem to infer a Boltzmann distribution for homologous protein sequences from their single-site and pairwise amino acid frequencies recently attracts a great deal of attention in the studies of protein structure and evolution. We study regularization and learning methods and how to tune regularization parameters to correctly infer interactions in Boltzmann machine learning. Using L2 regularization for fields, group L1 for couplings is shown to be very effective for sparse couplings in comparison with L2 and L1. Two regularization parameters are tuned to yield equal values for both the sample and ensemble averages of evolutionary energy. Both averages smoothly change and converge, but their learning profiles are very different between learning methods. The Adam method is modified to make stepsize proportional to the gradient for sparse couplings and to use a soft-thresholding function for group L1. It is shown by first inferring interactions from protein sequences and then from Monte Carlo samples that the fields and couplings can be well recovered, but that recovering the pairwise correlations in the resolution of a total energy is harder for the natural proteins than for the protein-like sequences. Selective temperature for folding/structural constrains in protein evolution is also estimated.
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Bousova K, Bednarova L, Zouharova M, Vetyskova V, Postulkova K, Hofbauerová K, Petrvalska O, Vanek O, Tripsianes K, Vondrasek J. The order of PDZ3 and TrpCage in fusion chimeras determines their properties-a biophysical characterization. Protein Sci 2021; 30:1653-1666. [PMID: 33969912 DOI: 10.1002/pro.4107] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 05/06/2021] [Accepted: 05/07/2021] [Indexed: 11/09/2022]
Abstract
Most of the structural proteins known today are composed of domains that carry their own functions while keeping their structural properties. It is supposed that such domains, when taken out of the context of the whole protein, can retain their original structure and function to a certain extent. Information on the specific functional and structural characteristics of individual domains in a new context of artificial fusion proteins may help to reveal the rules of internal and external domain communication. Moreover, this could also help explain the mechanism of such communication and address how the mutual allosteric effect plays a role in a such multi-domain protein system. The simple model system of the two-domain fusion protein investigated in this work consisted of a well-folded PDZ3 domain and an artificially designed small protein domain called Tryptophan Cage (TrpCage). Two fusion proteins with swapped domain order were designed to study their structural and functional features as well as their biophysical properties. The proteins composed of PDZ3 and TrpCage, both identical in amino acid sequence but different in composition (PDZ3-TrpCage, TrpCage-PDZ3), were studied using circualr dichroism (CD) spectrometry, analytical ultracentrifugation, and molecular dynamic simulations. The biophysical analysis uncovered different structural and denaturation properties of both studied proteins, revealing their different unfolding pathways and dynamics.
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Affiliation(s)
- Kristyna Bousova
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague 6, Czech Republic
| | - Lucie Bednarova
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague 6, Czech Republic
| | - Monika Zouharova
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague 6, Czech Republic.,Second Faculty of Medicine, Charles University, Prague 5, Czech Republic
| | - Veronika Vetyskova
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague 6, Czech Republic.,Department of Biochemistry and Microbiology, University of Chemistry and Technology Prague, Prague 6, Czech Republic
| | - Klara Postulkova
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague 6, Czech Republic.,Second Faculty of Medicine, Charles University, Prague 5, Czech Republic
| | - Kateřina Hofbauerová
- Faculty of Mathematics and Physics, Charles University, Prague 2, Czech Republic.,Institute of Microbiology of the Czech Academy of Sciences, Prague 4, Czech Republic
| | - Olivia Petrvalska
- Department of Structural Biology of Signalling Proteins, Division BIOCEV, Institute of Physiology, Vestec, Czech Republic
| | - Ondrej Vanek
- Department of Biochemistry, Faculty of Science, Charles University, Prague 2, Czech Republic
| | | | - Jiri Vondrasek
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague 6, Czech Republic
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Jurásek M, Kumar J, Paclíková P, Kumari A, Tripsianes K, Bryja V, Vácha R. Phosphorylation-induced changes in the PDZ domain of Dishevelled 3. Sci Rep 2021; 11:1484. [PMID: 33452274 PMCID: PMC7810883 DOI: 10.1038/s41598-020-79398-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 12/04/2020] [Indexed: 01/29/2023] Open
Abstract
The PDZ domain of Dishevelled 3 protein belongs to a highly abundant protein recognition motif which typically binds short C-terminal peptides. The affinity of the PDZ towards the peptides could be fine-tuned by a variety of post-translation modifications including phosphorylation. However, how phosphorylations affect the PDZ structure and its interactions with ligands remains elusive. Combining molecular dynamics simulations, NMR titration, and biological experiments, we explored the role of previously reported phosphorylation sites and their mimetics in the Dishevelled PDZ domain. Our observations suggest three major roles for phosphorylations: (1) acting as an on/off PDZ binding switch, (2) allosterically affecting the binding groove, and (3) influencing the secondary binding site. Our simulations indicated that mimetics had similar but weaker effects, and the effects of distinct sites were non-additive. This study provides insight into the Dishevelled regulation by PDZ phosphorylation. Furthermore, the observed effects could be used to elucidate the regulation mechanisms in other PDZ domains.
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Affiliation(s)
- Miroslav Jurásek
- National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice 753/5, 625 00, Brno, Czech Republic
| | - Jitender Kumar
- CEITEC - Central European Institute of Technology, Masaryk University, Kamenice 753/5, 625 00, Brno, Czech Republic
| | - Petra Paclíková
- Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, 62500, Czech Republic
| | - Alka Kumari
- Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, 62500, Czech Republic
| | - Konstantinos Tripsianes
- CEITEC - Central European Institute of Technology, Masaryk University, Kamenice 753/5, 625 00, Brno, Czech Republic
| | - Vítězslav Bryja
- Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, 62500, Czech Republic
- Institute of Biophysics, Academy of Sciences of the Czech Republic, v.v.i., Brno, 612 65, Czech Republic
| | - Robert Vácha
- National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice 753/5, 625 00, Brno, Czech Republic.
- CEITEC - Central European Institute of Technology, Masaryk University, Kamenice 753/5, 625 00, Brno, Czech Republic.
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Selection originating from protein stability/foldability: Relationships between protein folding free energy, sequence ensemble, and fitness. J Theor Biol 2017; 433:21-38. [DOI: 10.1016/j.jtbi.2017.08.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Revised: 07/27/2017] [Accepted: 08/21/2017] [Indexed: 11/19/2022]
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Using the folding landscapes of proteins to understand protein function. Curr Opin Struct Biol 2016; 36:67-74. [PMID: 26812092 DOI: 10.1016/j.sbi.2016.01.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2015] [Revised: 12/31/2015] [Accepted: 01/06/2016] [Indexed: 11/20/2022]
Abstract
Proteins fold on a biologically-relevant timescale because of a funnel-shaped energy landscape. This landscape is sculpted through evolution by selecting amino-acid sequences that stabilize native interactions while suppressing stable non-native interactions that occur during folding. However, there is strong evolutionary selection for functional residues and these cannot be chosen to optimize folding. Their presence impacts the folding energy landscape in a variety of ways. Here, we survey the effects of functional residues on folding by providing several examples. We then review how such effects can be detected computationally and be used as assays for protein function. Overall, an understanding of how functional residues modulate folding should provide insights into the design of natural proteins and their homeostasis.
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Bhat HF, Adams ME, Khanday FA. Syntrophin proteins as Santa Claus: role(s) in cell signal transduction. Cell Mol Life Sci 2013; 70:2533-54. [PMID: 23263165 PMCID: PMC11113789 DOI: 10.1007/s00018-012-1233-9] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2012] [Revised: 11/21/2012] [Accepted: 12/03/2012] [Indexed: 11/30/2022]
Abstract
Syntrophins are a family of cytoplasmic membrane-associated adaptor proteins, characterized by the presence of a unique domain organization comprised of a C-terminal syntrophin unique (SU) domain and an N-terminal pleckstrin homology (PH) domain that is split by insertion of a PDZ domain. Syntrophins have been recognized as an important component of many signaling events, and they seem to function more like the cell's own personal 'Santa Claus' that serves to 'gift' various signaling complexes with precise proteins that they 'wish for', and at the same time care enough for the spatial, temporal control of these signaling events, maintaining overall smooth functioning and general happiness of the cell. Syntrophins not only associate various ion channels and signaling proteins to the dystrophin-associated protein complex (DAPC), via a direct interaction with dystrophin protein but also serve as a link between the extracellular matrix and the intracellular downstream targets and cell cytoskeleton by interacting with F-actin. They play an important role in regulating the postsynaptic signal transduction, sarcolemmal localization of nNOS, EphA4 signaling at the neuromuscular junction, and G-protein mediated signaling. In our previous work, we reported a differential expression pattern of alpha-1-syntrophin (SNTA1) protein in esophageal and breast carcinomas. Implicated in several other pathologies, like cardiac dys-functioning, muscular dystrophies, diabetes, etc., these proteins provide a lot of scope for further studies. The present review focuses on the role of syntrophins in membrane targeting and regulation of cellular proteins, while highlighting their relevance in possible development and/or progression of pathologies including cancer which we have recently demonstrated.
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Affiliation(s)
- Hina F Bhat
- Department of Biotechnology, University of Kashmir, Srinagar, Jammu and Kashmir, India.
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