Topic: Recent Developments on Molecular Mechanism of Protein Transport in a Living Cell
OBJECTIVE OF GUEST LECTURE:
The targeted incorporation of proteins into the membrane is a vital process for cell maintenance; these membrane proteins ensure the proper functioning of the cell’s metabolism, communication with its environment, and energy supply. Protein-sorting mechanisms ensure that membrane proteins are specifically recognized among thousands of different proteins — and are sent to the membrane, where they are needed. The mechanism is shown by vesicular transport.
GUEST SPEAKER: PROF. GURUSHARAN SINGH RANDHAWA
Department of Biotechnology, Indian Institute of Technology, Roorkee Gursharn Singh Randhawa has done his M. Sc. (1976) and Ph. D. in Genetics (1980) from Punjab Agricultural University, Ludhiana. He worked as an I. T. C. fellow in the Biological Research Center, Szeged, Hungary (1980-82) and Research Associate in the Jawaharlal Nehru University, New Delhi (1982-84). He joined University of Roorkee as a Lecturer in 1984 and was promoted as a Reader in 1986. He has been serving Indian Institute of Technology (I. I. T.) Roorkee as a Professor since 1996. He served as the Head of the Department of Biotechnology, I. I. T. Roorkee from January 1, 2004 to January 2, 2007. He worked as a Visiting Scientist in the Pioneer Hi-Bred International Inc., Johnston, U. S. A. (2001) and North Dakota State University, Fargo, U. S. A. (2005). His research work has been published in prestigious international journals like Science, Molecular and General Genetics, Journal of Bacteriology and Frontiers in Plant Science. He has supervised 31 Ph. D. theses and 67 M. Sc. dissertations. His important assignments include the membership of the Editorial Boards of the Indian Journal of Microbiology- a journal published by Springer Verlag, Germany (2006-2011) and the Indian Journal of Experimental Biology- a journal published by C.S.I.R., India (2007-2009), membership of the Court, Banaras Hindu University, Academic Advisor Biology in the Environmental Working Group of the Feasibility Study (carried out by Japan International Cooperation Agency, Japan) of the Dedicated Freight Corridor (DFC) Project , Ministry of Railways, Govt. of India, and member, National Jury, Agilent Engineering and Technology Awards – 2007 & 2008 (Awards given by Agilent Technologies, U. S. A.). Recently he has been nominated for three years (2017-2020) as a Member of the Board of Governors of Forest Research Institute University, Dehradun by the Director-General, Indian Council of Forestry Research and Education, Government of India.
Proteins only exist for a certain period and are then degraded and recycled by the cell’s machinery through the process of protein turnover. A protein’s lifespan is measured in terms of its half-life and covers a wide range. They can exist for minutes or years with an average lifespan of 1–2 days in mammalian cells. Abnormal or misfolded proteins are degraded more rapidly either due to being targeted for destruction or due to being unstable. Proteins are essential parts of organisms and participate in virtually every process within cells. Many proteins are enzymes that catalyse biochemical reactions and are vital to metabolism. Proteins also have structural or mechanical functions, such as actin and myosin in muscle and the proteins in the cytoskeleton, which form a system of scaffolding that maintains cell shape. Other proteins are important in cell signaling, immune responses, cell adhesion, and the cell cycle. In animals, proteins are needed in the diet to provide the essential amino acids that cannot be synthesized. Digestion breaks the proteins down for use in the metabolism.
Activities/points/ knowledge learned by students:
Transport of proteins from one location to another is required for the normal functioning of a living cell. This transport is achieved by several mechanisms. One of the most common mechanisms is vesicular trafficking in which the protein to be transported is enclosed in a membranous vesicle. Heterotetrameric protein complexes play a major role in vesicular trafficking. Five such complexes, namely, AP1, AP2, AP3, AP4 and AP5 have been identified and characterized. Each of these complexes consists of two large subunits, one medium subunit and one small subunit. These complexes are made up of -1-1-1, -2-2-2, -3-3-3, -4-4-4 and -5-5-5 subunits, respectively. A specific site on each complex recognizes a sorting signal on the protein to be transported and another site on the complex interacts with an accessory protein which may serve as a coat of the vesicle. A defect in any of the subunits results in the disruption of structure and function of the whole complex leading to abnormalities in protein transport in the cell, further leading to several diseases in human beings. The research findings mainly of the last two decades in this area will be presented in the lecture.
The overview of the guest lecture was achieving the depth of knowledge about genetics and to know advance research in this field.