Deciphering motor function/dysfunction using single-molecule biophysics.
Cytoskeletal motors are ATP-dependent force generating biological machines that perform diverse tasks such as, intracellular cargo transport, muscle contraction, cell division, and whole cell movement etc.
The non-prcessive Myosin-II motors drives contraction of skeletal and cardic muscles, while the processive actin-based molecular motor proteins such as myosin V is involved in intracellular transport. The principle aim of our research is to gain detailed understanding of the mechanisms by which different motors perform diverse roles.
With vital roles in nearly all aspects of cellular physiology, motor protein dysfunctions are intricately linked to several myopathies including heart disorder Familial hypertrophic cardiomyopathy (FHC) that affects 1 in 200 individuals worldwide. Clinical phenotypes display a high variability ranging from being asymptomatic, to rapidly progressive failing heart or sudden cardiac death in young individuals and competitive athletes.
We aim to gain comprehensive understanding of primary functional alteration of β-cardiac myosin as a consequence of point mutations. The motor dysfunction results into myocardial disorganization that leads to the hypertrophy of left ventricle.
Our experimental approaches include single molecule biophysical methods such as total internal reflection fluorescence microscopy (TIRFM), zero mode waveguides and optical trapping to obtain precise kinetic and mechanical insights of the motor proteins.
Our lab is funded by following grants:
- German Research Foundation (DFG)
- Hochschulinterne Förderung (HilF, MHH)
- Fritz Thyssen Foundation
- Modulatory roles of sub-components of motor proteins
- Designing new nano-biohybrid motors based on natural building blocks
- Single molecule analysis of mutant myosin motors implicated in human hypertrophic cardiomyopathy
- Epigenetic regulation of straited muscle physiology by ubiquitin-like proteins
We employ a diversed array of cutting-edge experimental approaches.
For in-depth analysis motor protein function, we mainly use single molecule biophysical methods such as Total Internal Reflection Fluorescence microscopy (TIRF-M), optical trapping and zero mode waveguides to obtain precise kinetic and mechanical insights of the motor proteins.
For our projects involving epigenetic regulation of muscle physiology, we use various biochemical and molecular biological tools such as in vivo Co-IP, protein network analysis by quantitative mass spectrometry, gene-expression array system, chromatin immunoprecipitation and ChIPseq etc.
- Acto-Myosin Cross-Bridge Stiffness Depends on the Nucleotide State of Myosin II. Wang T, Brenner B, Nayak A, and Amrute-Nayak M. Nano Letters, 2020 Sep 15. doi: 10.1021/acs.nanolett.0c02960. [Online ahead of print] PubMed
- Transformation of the Nonprocessive Fast Skeletal Myosin II into a Processive Motor. Amrute-Nayak M*, Nayak A, Steffen W, Tsiavaliaris G, Scholz T, Brenner B. Small. 2019 Jan 18:e1804313. doi: 10.1002/smll.201804313. (* - Corresponding author, IF - 9.598); PubMed
- MARK4 regulates NLRP3 positioning and inflammasome activation through a microtubule-dependent mechanism. Li X, Thome S, Ma X, Amrute-Nayak M, Finigan A, Kitt L, Masters L, James JR, Shi Y, Meng G, Mallat Z. Nat Commun. 2017 Jun 28. (IF - 12.353)
- ATP turnover by individual myosin molecules hints at two conformers of the myosin active site. Amrute-Nayak M, Lambeck KA, Radocaj A, Huhnt HE, Scholz T, Hahn N, Tsiavaliaris G, Walter WJ, Brenner B. Proc Natl Acad Sci U S A. 2014 Feb 18. (IF - 9.504)
- Single-molecule assays reveal that RNA localization signals regulate dynein-dynactin copy number on individual transcript cargoes. Amrute-Nayak M, Bullock SL. Nat Cell Biol. 2012 Feb 26. (IF - 20.06)
- Targeted optimization of a protein nanomachine for operation in biohybrid devices. Amrute-Nayak M, Diensthuber RP, Steffen W, Kathmann D, Hartmann FK, Fedorov R, Urbanke C, Manstein DJ, Brenner B, Tsiavaliaris G. Angew Chem Int Ed Engl. 2010. (IF - 12.10)
For my Masters (M. Sc.), I studied Biochemistry from Pune University, India.
For my PhD, I joined Prof Bernhard Brenner’s research lab at Medical School Hannover (MHH), Germany. Here I undertook a project that involved studying molecular motors using single-molecule fluorescence detection technique, Total internal reflection fluorescence microscopy.
For my post-doctoral research, I moved to Medical Research Council-Laboratory of Molecular Biology (MRC-LMB), Cambridge, UK to work with Dr. Simon Bullock. I investigated the molecular mechanism of cytoplasmic mRNA transport. We attempted to dissect the interaction of localization signals with the microtubule-based motors that guide the mRNA through complex cytoskeletal network and sort different mRNAs.
Since 2017, I have established my research group at Medical school Hannover, Germany. The main focus of my lab is to investigate the molecular mechanisms underlying motor protein function. Furthermore, we investigate the naturally occurring mutations in sarcomereic proteins implicated in hypertrophic cardiomyopathy (HCM) in humans.
Tianbang finished his doctoral studies in the research group of PD. Dr. Walter Steffen, Institute for Molecular-and Cell physiology, Hannover Medical School.
His PhD project involved:
- Investigation of the force generation mechanism of cytoplasmic dynein
- Development of Optical Trap Technique
Since July 2018 he is working as a postdoctoral researcher in the research group of Dr. Mamta Amrute-Nayak . His project involves studying the ‘Regulatory mechanisms governing Myosin II motor functions using single molecule optical trapping’.
- Increased Cell-Matrix Adhesion upon Constitutive Activation of Rho Proteins by Cytotoxic Necrotizing Factors from E. coli and Y. pseudotuberculosis. Martin May, Tanja Kolbe, Tianbang Wang, Gudula Schmidt, and Harald Genth. J Signal Transduct. 2012;2012:570183.
- Difference in F-actin depolymerization induced by toxin B from the Clostridium difficile strain VPI 10463 and toxin B from the variant Clostridium difficile serotype F strain 1470. May M, Wang T, Müller M, Genth H. Toxins (Basel). 2013 Jan 11;5(1):106-19.
- Mg2+-free ATP Regulates Native Cytoplasmic Dynein’s Processivity, VA Behrens, WJ Walter, C Peters, T Wang, B Brenner1, MA Geeves4, T Scholz1,5, W Steffen. FEBS Lett. 2018 Dec 21..
- The force generation of cytoplasmic dynein is load dependent. T Wang, WJ Walter, VA Behrens, W Steffen. Manuscript in preparation.
I finished my Master studies in Biology from Middle East Technical University (METU), Ankara, Turkey.
Since October 2020, I joined research group of Dr. Mamta Amrute-Nayak at the Institute for Molecular-and Cell physiology to pursue my doctoral studies. My project involves studying the cardiac myosin II mutations linked to cardiomyopathies using single-molecule investigation methods.
Research team member as a FWJ (Freiwilliges Wissenschaftliches Jahr) student from October 2018 - August 2019. Fabius is currently pursuing his bachelor studies in Physics at Zurich University.