What are Molecular motors ?                       Roop Mallik’s homepage              Steven Gross Lab page

 

 


Biographical sketch, Roop Mallik

 

 


Appointments

February 2006 onwards  

Faculty member

Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, India

2001-present

Postdoctoral Fellow

University of California Irvine, Department of Developmental and Cell Biology

2000-2001

Postdoctoral Fellow

Joint appointment at the National Centre for Biological Sciences, Bangalore, India and Tata Institute of Fundamental Research, Mumbai, India.  

1994-1999

Research Fellow

Department of Condensed Matter Physics, Tata Institute of Fundamental Research, Mumbai, India.  

 

Professional Preparation

University of California Irvine, Irvine, USA                    Biophysical studies of molecular motors and motor ensembles, Post doctoral Fellow (since 2001)

Tata Institute of Fundamental Research, India                Protein folding, Post doctoral Fellow (2000-2001)

Tata Institute of Fundamental Research, India                Condensed MatterPhysics, Ph.D.(1993-1999)

University of Allahabad, India                                       Physics, M.Sc. (1993)

 

Awards

Long-term Post-doctoral fellowship from the Human Frontier Science Program (HFSP).

Academic achievements and goals

Post-doctoral (2001 –    ; at The University of California Irvine, Irvine)

Ø      Constructed an optical trap for in-vitro measurements of molecular motor function.

Ø      Developed protocols for in vitro optical trap based measurements of dynein and kinesin motors.

Ø      Single molecule measurements of the molecular motor cytoplasmic dynein, proposed existence of a nanoscale gear mechanism in this molecular motor

Ø      Understanding complexity in molecular motor ensembles and cooperative behavior of molecular motors in an in vitro and in vivo context.

 

Post-doctoral (2000 – 2001; at Tata Institute of Fundamental Research, Mumbai)

Ø      Set up a laboratory at the Tata Institute, Mumbai for study of ultrafast protein dynamics. Designed & implemented a laser-induced setup to generate sub-millisecond pH jumps.

Ø      Used this instrument for direct visualization of sub-millisecond protonation dynamics in Green Fluorescent Protein. Proposed model for the protonation process and structure-function relationship in this protein (see publication list)

.   

Doctoral (1995-1999; at Tata Institute of Fundamental Research, Mumbai) 

(See Publication list below)

Ø      Established the importance of magnetic precursor effects when interpreting data in the field of Strongly Correlated Electron Systems (SCES).

Ø      First effort to study effect of magnetic field on electrical resistivity of a new class of materials. Proposed formation of magnetic polarons in metallic systems.

Ø      Novel observation of large inverse response of electrical resistivity to magnetic field in naturally occurring layered alloys- proposed unconventional mechanism for this phenomenon

Ø      Study of manganate oxides and the role of disorder in these materials with respect to their magnetoresistance behavior.

Ø      Built an instrument to measure heat capacity of alloys and metals at temperatures of 0.3 Kelvin and above. 

 

Research motivation

To obtain a quantitative understanding of complexity in specific biological systems. Biological processes typically require ensemble(s) proteins that interact with each other in a complex manner. An example of such a process is intra-cellular transport. This transport involves the motion of many kinds of cargoes on cellular “roadways“ by proteins called molecular motors (Go here for a basic understanding of the problem I am interested in). Intracellular transport is a central problem in biology because it is responsible for the organization of the cell, and its failure correlates with several forms of human disease. The application of some biophysical techniques to quantify molecular motor function is now well established. However, such experiments are largely restricted to understanding single molecular motors. It is not clear how relevant this is to the biology of the system, since the motors almost always function in vivo as part of a complex ensemble of other motor and non-motor proteins. My goal is to go beyond single motors and use biophysical techniques to characterize motor complexes.

 

Selected publications

(For a full list, Go here)

In Journals

1.      R. Mallik*, D. Petrov*, S. A. Lex, S.J. King and S.P. Gross, Building complexity: an in vitro study of cytoplasmic dynein with in vivo implications. Current Biology 15, 2075 (2005) (PDF File)

2.      M.P. Singh, R. Mallik, S.P. Gross and C. Yu, Monte Carlo modeling of Single Molecule Cytoplasmic Dynein. PNAS 102, 12059 (2005) (PDF File)

3.      R. Mallik and S.P. Gross, Molecular Motors: Strategies to get along  (Review article) Current Biology 14, R971 (2004) (PDF File)

4.      R. Mallik, B.C. Carter, S.A.Lex, S.J. King and S.P. Gross, Cytoplasmic dynein functions as a gear in response to load,

      Nature 427, p649 (2004)  (PDF File)

5.       R. Mallik, J.B. Udgaonkar and G. Krishnamoorthy, Kinetics of proton transfer in a green fluorescent protein: A laser-induced pH jump study. Proceedings of Indian Academy of Sciences (Chem Sci) 115, p307 (2003) (PDF File)

 

6.      E.V. Sampathkumaran, R. Mallik, P.L. Paulose & S. Majumdar (2000) Silence of magnetic layers to magnetoresistive process and eletronic separation at low temperatures in (La,Sm)Mn2Ge2, Phys. Lett. 71, 123. (PDF File)

7.      E.V. Sampathkumaran, Subham Majumdar, R. Mallik, R.Vijayraghavan, H. Wada and M. Shiga (2000). Unusually large negative magnetoresistance around 200 K in the alloys Gd1-xLax Mn2Ge2   J. Phys.: Cond. Matter 12, L399. (PDF File)

8.      S. R. Saha, H. Sugawara, T. D. Matsuda, H. Sato, R. Mallik and E. V. Sampathkumaran (1999). Magnetic anisotropy, first-order-like metamagnetic transitions and large negative magnetoresistance in the single crystal of Gd2PdSi3.   Phys Rev. B 60, 12162. (PDF File)

9.      S. Majumdar, R. Mallik, E.V. Sampathkumaran, K. Rupprecht and G. Wortmann (1999) Magnetic behaviour of Eu2CuSi3 : Large negative magnetoresistance above Curie temperature   Phys. Rev. B 60, 6770.(PDF File)

10.    Subham Majumdar, M. Mahesh Kumar, R. Mallik and E. V. Sampathkumaran (1999).  La substitution induced linear temperature dependence of electrical resistivity and Kondo behaviour in the alloys, Ce2-xLaxCoSi3  Solid State Communications 110, 509. (PDF File)

11.    R. Mallik, E.V. Sampathkumaran and P.L. Paulose (1997).Large positive magnetoresistance at low temperatures in a ferromagnetic natural multilayer, LaMn2Ge2 Applied Physics Letters 71, 2385. (PDF File)

12.    R. Mallik, P.L. Paulose, E.V. Sampathkumaran, S. Patil and V. Nagarajan (1997) Coexistence of localized and (induced) itinerant magnetism and heat-capacity anomalies in Gd1-xYx Ni alloys  Phys. Rev. B 55, 8369. (PDF File)

13.    R. Mallik, E.V. Sampathkumaran, P.L. Paulose and V. Nagarajan (1997)  Magnetoresistance in GdNi: Magnetic polaronic-like effect near the Curie temperature and low-temperature sign reversal  Phys. Rev. B 55, R8650 (Rapid Communication). (PDF File)

14.    (*) R. Mallik, E.V. Sampathkumaran and P.L. Paulose (1997) Kondo lattice behaviour and multiple characteristic temperatures in CeIr2 Ge2  Phys. Rev. B 55, 3627. (PDF File)

15.    R. Mallik, E.V. Sampathkumaran, J. Dumschat and G. Wortmann (1997). Magnetic ordering and spin fluctuation behaviour in compounds of the type Ce2(Pd,Rh)2In.  Solid State Communications 102, 59. (PDF File)

16.    R. Mallik and E.V. Sampathkumaran (1996). Magnetic behaviour of the alloys (Ce1-x Yx)2PdSi3  J. Magn. Magn. Mater. 164, L13. (PDF File)

17.    E.V. Sampathkumaran, P.L. Paulose and R. Mallik (1996) Magnetoresistance anomalies and multiple magnetic transitions in SmMn2Ge2. Phys. Rev. B 54, R3710 (Rapid Communication) (PDF File)

 

In Conference proceedings

18.    A.M. Saxena, R. Mallik, J.B. Udgaonkar and G. Krishnamoorthy,

       Protein dynamics controls proton transfer from bulk solvent to interior of proteins: a case study with GFP.

       8th Conference on Methods and Applications of Fluorescence: Spectroscopy, Imaging and Probes. Prague, 2003.

19.     S. Majumdar et. al.,                  Physica B 281&282 (2000) 367   (PDF File)

20.    S. Majumdar et. al.,                  Physica B 259&261 (1999) 166   (PDF File)

21.    R. Mallik et. al.,                        Physica B 259&261 (1999) 892   (PDF File)

22.    S. Majumdar et. al.,                  Physica B 259&261 (1999) 843   (PDF File)

23.    R. Mallik et. al.,                        Physica B 230&232 (1997) 169   (PDF File)

24.    R. Mallik et. al.,                        Physica B 230&232 (1997) 731   (PDF File)

25.    E.V. Sampathkumaran et. al.,    Physica B 223&224 (1996) 316   (PDF File)

26.    R. Mallik et. al.,                        Physica B 223&224 (1996) 382   (PDF File)