Jayanta Mukhopadhyay

Jayanta Mukhopadhyay
Associate Professor

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Previous appointments:

Howard Hughes Medical Institute/ Waksman Institute Rutgers University

Research interests:

Transcription is the first step in gene expression where most regulation occurs. RNAP core enzyme together with sigma factor(s) and/or numerous regulator(s) orchestrates the gene expression in bacteria. Our lab seeks to characterize the interactions among RNAP, sigma factors, and regulators required for various gene expressions in prokaryote, e.g. Escherichia coli, Bacillus subtilis and Mycobacterium tuberculosis. The proposed work will use integrated biophysical, biochemical and genetic approaches, along with a recombinant in vitro transcription system to address the following specific aims:

 

1. Mechanism of gene regulation by various transcriptional factors and sigma factors in prokaryote.

2. Study ‘sigma cycle’ paradigm in prokaryote

3. Identify and characterize inhibitors of M. tuberculosis gene expression. 

Contact:

Address: Department of Chemistry
Main Campus
Bose Institute
93/1, A. P. C. Road
Kolkata - 700 009, India
E-Mail: jayanta[at]jcbose.ac.in
Phone: +91-33-23031143

Research:

Novel mechanism of gene regulation: the protein Rv1222 of Mycobacterium tuberculosis inhibits transcription by anchoring the RNA polymerase onto DNA.

We propose a novel mechanism of gene regulation in Mycobacterium tuberculosis where the protein Rv1222 inhibits transcription by anchoring RNA polymerase (RNAP) onto DNA. In contrast to our existing knowledge that transcriptional repressors function by either binding to DNA at specific sequences or by binding to RNAP, we show that Rv1222 mediated transcription inhibition requires simultaneous binding of the protein to both RNAP and DNA.  The proposed mechanism by which Rv1222 inhibits transcription reveals a new repertoire of prokaryotic gene regulation.


Promoter escape with bacterial two-component sigma factor suggests retention of sigma region two in the elongation complex.

The transition from the formation of RNAP-promoter open complex step to productive elongation complex step involves ‘promoter escape’ of RNAP. From the structure of RNAP, a ‘promoter escape’ model has been proposed which suggests that the interactions between sR4 and RNAP and sR4 and DNA are destabilized upon transition to elongation. This accounts for reduced affinity of s to RNAP and stochastic release of s. Using a two- component s factor YvrI and YvrHa from Bacillus subtilis that independently contribute to the functions of sR4 and sR2 in a RNAP-promoter complex, we show that YvrI, that mimics sR4, is released gradually as transcription elongation proceeds whereas YvrHa that mimics sR2 is retained throughout the elongation complexes. Thus our result validates the proposed model for promoter escape and also suggests that promoter escape involves little or no change in the interaction of sR2 with RNAP.


Bacillus subtilis d factor functions as a transcriptional regulator 

Most bacterial RNA polymerases (RNAP) contain five conserved subunits viz. 2a, b, b’ and w. However, in many gram positive bacteria, especially in fermicutes, RNAP is associated with an additional factor, called d.  Over three decades since its identification, it had been thought that d functioned as a subunit of RNAP to enhance the level of transcripts by recycling RNAP.  Performing biochemical and mutational analysis we show that Bacillus subtilis d is not a subunit of RNAP, but function as a transcriptional regulator.


Recombinant reporter assay: Using three-plasmid expression system in E. coli, We develop a recombinant reporter assay would render a new and efficient avenue to monitor the interactions among M. tuberculosis RNAP, s factors, transcription factors and their cognate promoters in vivo without the hazard of handling the  pathogenic, slow growing bacteria.



Publications:

1.      Prajapati RK, Sur R, Mukhopadhyay J*.  A Novel function of d factor from Bacillus subtilis as a transcriptional repressor (2016) J Biol Chem. 291(46): 24029-24035.

2.      Datta A, Yadav V, Ghosh A, Choi J, Bhattacharyya D,. Kar R K, Ilyas H, Dutta A, An E, Mukhopadhyay J, Lee D, Sanyal K, Ramamoorthy A, and Bhunia A. Mode of Action of a Designed Antimicrobial Peptide:High Potency Against Cryptococcus neoformans. (2016) Biophysical Journal 111: 1724–1737

3.      Roy A, Dutta A, Roy D, Ganguly P, Ghosh R, Kar RK, Bhunia A, Mukhopadhyay J, and Chaudhuri S. Deciphering the role of the AT-rich interaction domain and the HMG-box domain of ARID-HMG proteins of Arabidopsis thaliana. (2106) Plant Molecular Biology 92(3):389-390.

4.      Prajapati RK, Sengupta S, Rudra P, Mukhopadhyay J*. Bacillus subtilis δ Factor Functions as a Transcriptional Regulator by Facilitating the Open Complex Formation. (2016) J Biol Chem. 291(3):1064-75.

5.      Promoter escape with bacterial two-component sigma factor suggests retention of sigma region two in the elongation complex. Sengupta S, Prajapati RK, and Mukhopadhyay J*. (2015) J Biol Chem. 290(47):28575-83.

6.      Rudra P, Prajapati RK, Banerjee R, Sengupta S, and Mukhopadhyay J*. Novel mechanism of gene regulation: the protein Rv1222 of Mycobacterium tuberculosis inhibits transcription by anchoring the RNA polymerase onto DNA. (2015)  Nucleic Acid Research, 43: 5855-67.

7.      Saha A, Mukhopadhyay J, Datta AB, Parrack P. Revisiting the mechanism of activation of cyclic AMP receptor protein (CRP) by cAMP in Escherichia coli: Lessons from a subunit-crosslinked form of CRP. (2015)  FEBS Letters 589: 358–363.

8.      Sharma AK, Chatterjee A, Gupta S, Banerjee R, Mandal S, Mukhopadhyay J, Basu J, Kundu M. MtrA, an essential response regulator of the MtrAB two component system regulates the  transcription of resuscitation promoting factor B (RpfB) of Mycobacterium tuberculosis. (2015) Microbiology 161(6):1271-81.

9.      Banerjee R, Rudra ., Saha A, and Mukhopadhyay J*. Recombinant Reporter Assay Using Transcriptional Machinery of Mycobacterium tuberculosis. (2015) Journal of bacteriology 197, 646-653.

10.     Banerjee R, Rudra P, Prajapati, RK, Sengupta S., and Mukhopadhyay J*. Optimization of recombinant Mycobacterium tuberculosis RNA polymerase expression and purification. (2014) Tuberculosis (Edinb) 94:397-404.

11.   Polyphosphate kinase 1, a central node in the stress response network of Mycobacterium tuberculosis, connects the two-component systems MprAB, SenX3-Reg X3 and the extra-cytoplasmic function sigma factor, Sigma E. Sanyal S, Banerjee, S K Banerjee, R, Mukhopadhyay J,  Kundu, M. (2013) Microbiology 159: 2074-86. 

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Recognition:

    Teaching:

    Courses offered for MSc  (Life Sciences)

    Thermodynamic concept of protein-ligand interactions 


    Present:

    Image Name Designation Department Campus Contact number Email
    profile image Aniruddha Tewary JRF Integrated M.Sc. Ph.D. Centenary 25693311 aniruddhatewary@gmail.com
    profile image Arkajyoti Dutta SRF Chemistry Main 23031143 arkajyoti
    profile image Madhurima Chatterjee JRF Chemistry Main madhurima20ster@gmail.com
    profile image Manish Prakash Victor SRF Bioinformatics Centre Main 25693275 manish.pvictor@gmail.co
    profile image Ritu Jaiswal JRF Chemistry Main 23031143 ritujaiswal1111
    profile image Sourajit Saha JRF Chemistry Main 23031143 sourajitsaha92@mail.jcbose.ac.in

    Former:

    Current members:

    1.  Arkajyoti Dutta,  SRF (2013 -)

    2. Ritu Jaiswal, JRF  (2017)

    3. Sourajit Saha, JRF (2017)

    4. Dr. Soumya Mukherjee,  SERB- N PDFellow (2017)

    5 Nilika Bhattacharyya MSc Project student

    6 Aniruddha Tewary MSc Project student


    Past members:

    1.   Rajdeep Banerjee (2009-2014); Ph. D awarded 2014, current position: Post-doctoral fellow at Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public Health

    2.   Paulami Rudra (2009-2015); Ph.D awarded 2016, current position: Post-doctoral fellow at  NYSDOH Wadsworth Center , U of Albany School of Pub Health , Albany.

    3.   Ranjit  Kumar Prajapati (2009-2015) Ph.D awarded 2016, current position: Post-doctoral fellow at Department of Biochemistry and Food Chemistry, University of Turku, Finland

    4.   Shreya Sengupta (2009-2015) Ph.D awarded 2016, current position: Post-doctoral fellow at Biochemistry and Molecular Biology, Pennstate University, USA

    5. Dr. Sangita Majumdar RA (2012- 2014)


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