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Selvaraj MK, Thakur A, Kumar M, Pinnaka AK, Suri CR, Siddhardha B, Elumalai SP. Ion-pumping microbial rhodopsin protein classification by machine learning approach. BMC Bioinformatics 2023; 24:29. [PMID: 36707759 PMCID: PMC9881276 DOI: 10.1186/s12859-023-05138-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 01/04/2023] [Indexed: 01/28/2023] Open
Abstract
BACKGROUND Rhodopsin is a seven-transmembrane protein covalently linked with retinal chromophore that absorbs photons for energy conversion and intracellular signaling in eukaryotes, bacteria, and archaea. Haloarchaeal rhodopsins are Type-I microbial rhodopsin that elicits various light-driven functions like proton pumping, chloride pumping and Phototaxis behaviour. The industrial application of Ion-pumping Haloarchaeal rhodopsins is limited by the lack of full-length rhodopsin sequence-based classifications, which play an important role in Ion-pumping activity. The well-studied Haloarchaeal rhodopsin is a proton-pumping bacteriorhodopsin that shows promising applications in optogenetics, biosensitized solar cells, security ink, data storage, artificial retinal implant and biohydrogen generation. As a result, a low-cost computational approach is required to identify Ion-pumping Haloarchaeal rhodopsin sequences and its subtype. RESULTS This study uses a support vector machine (SVM) technique to identify these ion-pumping Haloarchaeal rhodopsin proteins. The haloarchaeal ion pumping rhodopsins viz., bacteriorhodopsin, halorhodopsin, xanthorhodopsin, sensoryrhodopsin and marine prokaryotic Ion-pumping rhodopsins like actinorhodopsin, proteorhodopsin have been utilized to develop the methods that accurately identified the ion pumping haloarchaeal and other type I microbial rhodopsins. We achieved overall maximum accuracy of 97.78%, 97.84% and 97.60%, respectively, for amino acid composition, dipeptide composition and hybrid approach on tenfold cross validation using SVM. Predictive models for each class of rhodopsin performed equally well on an independent data set. In addition to this, similar results were achieved using another machine learning technique namely random forest. Simultaneously predictive models performed equally well during five-fold cross validation. Apart from this study, we also tested the own, blank, BLAST dataset and annotated whole-genome rhodopsin sequences of PWS haloarchaeal isolates in the developed methods. The developed web server ( https://bioinfo.imtech.res.in/servers/rhodopred ) can identify the Ion Pumping Haloarchaeal rhodopsin proteins and their subtypes. We expect this web tool would be useful for rhodopsin researchers. CONCLUSION The overall performance of the developed method results show that it accurately identifies the Ionpumping Haloarchaeal rhodopsin and their subtypes using known and unknown microbial rhodopsin sequences. We expect that this study would be useful for optogenetics, molecular biologists and rhodopsin researchers.
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Affiliation(s)
- Muthu Krishnan Selvaraj
- grid.418099.dMTCC-Microbial Type Culture Collection and Gene Bank, Institute of Microbial Technology, Council of Scientific and Industrial Research (CSIR-IMTECH), Chandigarh, 160036 India
| | - Anamika Thakur
- grid.418099.dVirology Unit and Bioinformatics Centre, Institute of Microbial Technology, Council of Scientific and Industrial Research (CSIR-IMTECH), Chandigarh, 160036 India
| | - Manoj Kumar
- grid.418099.dVirology Unit and Bioinformatics Centre, Institute of Microbial Technology, Council of Scientific and Industrial Research (CSIR-IMTECH), Chandigarh, 160036 India
| | - Anil Kumar Pinnaka
- grid.418099.dMTCC-Microbial Type Culture Collection and Gene Bank, Institute of Microbial Technology, Council of Scientific and Industrial Research (CSIR-IMTECH), Chandigarh, 160036 India
| | - Chander Raman Suri
- grid.418099.dBiosensor Department, Institute of Microbial Technology, Council of Scientific and Industrial Research (CSIR-IMTECH), Chandigarh, 160036 India
| | - Busi Siddhardha
- grid.412517.40000 0001 2152 9956Department of Microbiology, School of Life Sciences, Pondicherry University, Puducherry, 605014 India
| | - Senthil Prasad Elumalai
- grid.418099.dBiochemical Engineering Research and Process Development Centre, Institute of Microbial Technology, Council of Scientific and Industrial Research (CSIR-IMTECH), Chandigarh, 160036 India
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Fakhoury M. Optogenetics: A revolutionary approach for the study of depression. Prog Neuropsychopharmacol Biol Psychiatry 2021; 106:110094. [PMID: 32890694 DOI: 10.1016/j.pnpbp.2020.110094] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Revised: 08/13/2020] [Accepted: 08/30/2020] [Indexed: 10/24/2022]
Abstract
Depression is a severe and chronic mental disorder that affects millions of individuals worldwide. Symptoms include depressed mood, loss of interest, reduced motivation and suicidal thoughts. Even though findings from genetic, molecular and imaging studies have helped provide some clues regarding the mechanisms underlying depression-like behaviors, there are still many unanswered questions that need to be addressed. Optogenetics, a technique developed in the early 2000s, has proved effective in the study and treatment of depression and depression-like behaviors and has revolutionized already known experimental techniques. This technique employs light and genetic tools to either inhibit or excite specific neurons or pathways within the brain. In this review paper, an up-to-date understanding of the use of optogenetics in the study of depression-like behaviors is provided, along with suggestions for future research directions.
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Affiliation(s)
- Marc Fakhoury
- Department of Natural Sciences, School of Arts and Sciences, Lebanese American University, Beirut Campus, Lebanon.
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Verma DK, Chaudhary C, Singh L, Sidhu C, Siddhardha B, Prasad SE, Thakur KG. Isolation and Taxonomic Characterization of Novel Haloarchaeal Isolates From Indian Solar Saltern: A Brief Review on Distribution of Bacteriorhodopsins and V-Type ATPases in Haloarchaea. Front Microbiol 2020; 11:554927. [PMID: 33362726 PMCID: PMC7755889 DOI: 10.3389/fmicb.2020.554927] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 09/17/2020] [Indexed: 01/10/2023] Open
Abstract
Haloarchaea inhabit high salinity environments worldwide. They are a potentially rich source of crucial biomolecules like carotenoids and industrially useful proteins. However, diversity in haloarchaea present in Indian high salinity environments is poorly studied. In the present study, we isolated 12 haloarchaeal strains from hypersaline Kottakuppam, Tamil Nadu solar saltern in India. 16S rRNA based taxonomic characterization of these isolates suggested that nine of them are novel strains that belong to genera Haloarcula, Halomicrobium, and Haloferax. Transmission electron microscopy suggests the polymorphic nature of these haloarchaeal isolates. Most of the haloarchaeal species are known to be high producers of carotenoids. We were able to isolate carotenoids from all these 12 isolates. The UV-Vis spectroscopy-based analysis suggests that bacterioruberin and lycopene are the major carotenoids produced by these isolates. Based on the visual inspection of the purified carotenoids, the isolates were classified into two broad categories i.e., yellow and orange, attributed to the differences in the ratio of bacterioruberin and lycopene as confirmed by the UV-Vis spectral analysis. Using a PCR-based screening assay, we were able to detect the presence of the bacteriorhodopsin gene (bop) in 11 isolates. We performed whole-genome sequencing for three bop positive and one bop negative haloarchaeal isolates. Whole-genome sequencing, followed by pan-genome analysis identified multiple unique genes involved in various biological functions. We also successfully cloned, expressed, and purified functional recombinant bacteriorhodopsin (BR) from one of the isolates using Escherichia coli as an expression host. BR has light-driven proton pumping activity resulting in the proton gradient across the membrane, which is utilized by V-Type ATPases to produce ATP. We analyzed the distribution of bop and other accessory genes involved in functional BR expression and ATP synthesis in all the representative haloarchaeal species. Our bioinformatics-based analysis of all the sequenced members of genus Haloarcula suggests that bop, if present, is usually inserted between the genes coding for B and D subunits of the V-type ATPases operon. This study provides new insights into the genomic variations in haloarchaea and reports expression of new BR variant having good expression in functional form in E. coli.
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Affiliation(s)
- Dipesh Kumar Verma
- Structural Biology Laboratory, G. N. Ramachandran Protein Centre, Council of Scientific and Industrial Research-Institute of Microbial Technology (CSIR-IMTECH), Chandigarh, India
| | - Chetna Chaudhary
- Structural Biology Laboratory, G. N. Ramachandran Protein Centre, Council of Scientific and Industrial Research-Institute of Microbial Technology (CSIR-IMTECH), Chandigarh, India
| | - Latika Singh
- Structural Biology Laboratory, G. N. Ramachandran Protein Centre, Council of Scientific and Industrial Research-Institute of Microbial Technology (CSIR-IMTECH), Chandigarh, India
| | - Chandni Sidhu
- MTCC-Microbial Type Culture Collection & Gene Bank, Council of Scientific and Industrial Research Institute of Microbial Technology (CSIR-IMTECH), Chandigarh, India
| | - Busi Siddhardha
- Department of Microbiology, School of Life Sciences, Pondicherry University, Puducherry, India
| | - Senthil E Prasad
- Biochemical Engineering Research and Process Development Centre, Council of Scientific and Industrial Research-Institute of Microbial Technology (CSIR-IMTECH), Chandigarh, India
| | - Krishan Gopal Thakur
- Structural Biology Laboratory, G. N. Ramachandran Protein Centre, Council of Scientific and Industrial Research-Institute of Microbial Technology (CSIR-IMTECH), Chandigarh, India
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Chen H, Simoska O, Lim K, Grattieri M, Yuan M, Dong F, Lee YS, Beaver K, Weliwatte S, Gaffney EM, Minteer SD. Fundamentals, Applications, and Future Directions of Bioelectrocatalysis. Chem Rev 2020; 120:12903-12993. [DOI: 10.1021/acs.chemrev.0c00472] [Citation(s) in RCA: 118] [Impact Index Per Article: 29.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Hui Chen
- Department of Chemistry, University of Utah, 315 South 1400 East, RM 2020, Salt Lake City, Utah 84112, United States
| | - Olja Simoska
- Department of Chemistry, University of Utah, 315 South 1400 East, RM 2020, Salt Lake City, Utah 84112, United States
| | - Koun Lim
- Department of Chemistry, University of Utah, 315 South 1400 East, RM 2020, Salt Lake City, Utah 84112, United States
| | - Matteo Grattieri
- Department of Chemistry, University of Utah, 315 South 1400 East, RM 2020, Salt Lake City, Utah 84112, United States
| | - Mengwei Yuan
- Department of Chemistry, University of Utah, 315 South 1400 East, RM 2020, Salt Lake City, Utah 84112, United States
| | - Fangyuan Dong
- Department of Chemistry, University of Utah, 315 South 1400 East, RM 2020, Salt Lake City, Utah 84112, United States
| | - Yoo Seok Lee
- Department of Chemistry, University of Utah, 315 South 1400 East, RM 2020, Salt Lake City, Utah 84112, United States
| | - Kevin Beaver
- Department of Chemistry, University of Utah, 315 South 1400 East, RM 2020, Salt Lake City, Utah 84112, United States
| | - Samali Weliwatte
- Department of Chemistry, University of Utah, 315 South 1400 East, RM 2020, Salt Lake City, Utah 84112, United States
| | - Erin M. Gaffney
- Department of Chemistry, University of Utah, 315 South 1400 East, RM 2020, Salt Lake City, Utah 84112, United States
| | - Shelley D. Minteer
- Department of Chemistry, University of Utah, 315 South 1400 East, RM 2020, Salt Lake City, Utah 84112, United States
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Verma DK, Vasudeva G, Sidhu C, Pinnaka AK, Prasad SE, Thakur KG. Biochemical and Taxonomic Characterization of Novel Haloarchaeal Strains and Purification of the Recombinant Halotolerant α-Amylase Discovered in the Isolate. Front Microbiol 2020; 11:2082. [PMID: 32983058 PMCID: PMC7490331 DOI: 10.3389/fmicb.2020.02082] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Accepted: 08/07/2020] [Indexed: 11/13/2022] Open
Abstract
Haloarchaea are salt-loving archaea and potential source of industrially relevant halotolerant enzymes. In the present study, three reddish-pink, extremely halophilic archaeal strains, namely wsp1 (wsp-water sample Pondicherry), wsp3, and wsp4, were isolated from the Indian Solar saltern. The phylogenetic analysis based on 16S rRNA gene sequences suggests that both wsp3 and wsp4 strains belong to Halogeometricum borinquense while wsp1 is closely related to Haloferax volcanii species. The comparative genomics revealed an open pangenome for both genera investigated here. Whole-genome sequence analysis revealed that these isolates have multiple copies of industrially/biotechnologically important unique genes and enzymes. Among these unique enzymes, for recombinant expression and purification, we selected four putative α-amylases identified in these three isolates. We successfully purified functional halotolerant recombinant Amy2, from wsp1 using pelB signal sequence-based secretion strategy using Escherichia coli as an expression host. This method may prove useful to produce functional haloarchaeal secretory recombinant proteins suitable for commercial or research applications. Biochemical analysis of Amy2 suggests the halotolerant nature of the enzyme having maximum enzymatic activity observed at 1 M NaCl. We also report the isolation and characterization of carotenoids purified from these isolates. This study highlights the presence of several industrially important enzymes in the haloarchaeal strains which may potentially have improved features like stability and salt tolerance suitable for industrial applications.
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Affiliation(s)
- Dipesh Kumar Verma
- G. N. Ramachandran Protein Centre, Structural Biology Laboratory, Council of Scientific and Industrial Research-Institute of Microbial Technology, Chandigarh, India
| | - Gunjan Vasudeva
- MTCC-Microbial Type Culture Collection and Gene Bank, CSIR-Institute of Microbial Technology, Chandigarh, India
| | - Chandni Sidhu
- MTCC-Microbial Type Culture Collection and Gene Bank, CSIR-Institute of Microbial Technology, Chandigarh, India
| | - Anil K Pinnaka
- MTCC-Microbial Type Culture Collection and Gene Bank, CSIR-Institute of Microbial Technology, Chandigarh, India
| | - Senthil E Prasad
- Biochemical Engineering Research and Process Development Centre, Council of Scientific and Industrial Research-Institute of Microbial Technology, Chandigarh, India
| | - Krishan Gopal Thakur
- G. N. Ramachandran Protein Centre, Structural Biology Laboratory, Council of Scientific and Industrial Research-Institute of Microbial Technology, Chandigarh, India
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