Research Interest:

Molecular mechanism of stress, aging and cancer; gene silencing and imaging to understand the mechanism of action of Ayurvedic herb, Ashwagandha and others.

Education &Professional Career:

Dr. Sunil Kaul was born and brought up in Kalimpong (Darjeeling).  He obtained his MPhil and PhD degrees from the University of Delhi, India.  After his initial post-doctoral training, he was appointed as a researcher at the National Institute of Advanced Industrial Science & Technology (AIST) in Japan, and has been working there for last 30 years. He is now a Chief Senior Research Scientist.  His major research interest is to understand the molecular mechanism of stress, aging and cancer. He has been merging the traditional knowledge with modern technologies like gene silencing and imaging to understand the mechanism of action of Ayurvedic herb, Ashwagandha and others.  He is a coordinator of the DBT (India)-AIST (Japan) International Laboratory for Advanced Biomedicine at AIST, Japan.  With more than 200 research publications in International peer revised journals and several invited talks Internationally, he has been in Editorial board of several scientific journals.He is a Fellow of Geriatrics Society of India (FGSI), Overseas Fellow of Biotech Research Society of India (FBRSI), Fellow of Indian Academy of Neuroscience (FIAN), and Foreign Fellow of National Academy of Sciences, India (FNASc).

Affiliation & Contact:

Chief Senior Research Scientist, International Coordinator, DBT–AIST International Center for Translational and Environmental Research (DAICENTER), National Institute of Advanced Industrial Science & Technology (AIST)
Central 5-1, 1-1-1 Higashi, Tsukuba – 305 8565, Japan
Tel: +81 29 861 6713
E-mail: s-kaul@aist.go.jp

Abstract

Chromosome condensation is essential for the faithful transmission of genetic information to daughter cells during cell division.However, the chromosome condensation process has been still poorly understood. Here I introduce two factors, chromosome scaffold structure and divalent cations, are required for chromosome condensation. Chromosome scaffold was found in chromosome arms as an axial structure of chromosome and it has important role in chromosome construction. The scaffold structure has been observed as a single tick axis in a single chromatid. Using super-resolution microscopy and electron microscopy, I revealed that the scaffold structure mainly consists of two thin axes. It will generate stiffness and elasticity to chromosome. Although chromosome structure was severely changed without chromosome scaffold structure, chromosome condensation itself can be achieved by another factor, divalent cations. One of divalent cations, Ca²⁺ depletion caused defects in proper mitotic progression and chromosome condensation after the breakdown of the nuclear envelope. Fluorescence lifetime imaging microscopy-Förster resonance energy transfer and electron microscopy demonstrated that chromosome condensation is influenced by Ca²⁺. Ca²⁺ is also required for stabilization of kinetochore microtubules by loading CENP-F to kinetochore. Thus, combination of several imaging techniques is highly advantageous to understand chromosome structure.