Prof. Garini's Lab
Head - Nano-Bio-Photonics Lab
Prof. Yuval Garini is a Professor in the Department of Physics and member of the Nano Photonics Center at the Institute of Nanotechnology and Advanced Materials (BINA).
Garini and his group focus on the field of physical biology. Their research combines the development of imaging methods for the study of sub-cellular biology and genetics with the use of advanced single molecule detection techniques to explore various biological systems. A few of their research studies are described below.
Genome Organization in the Nucleus and Transcription
Garini’s group uses live cell imaging to study nuclear dynamics and to better understand genome organization and various cell processes in vivo on a single molecule level.
One example of this is disruption of telomeric proteins. In addition, the group collaborates with Prof. Yaron Shav-Tal's team to investigate transcription at a single-copy gene level in living cells. Using live cell imaging techniques, they study transcription rates and variation in the number of RNA polymerases transcribing on the gene.
This enables them to quantify single event statistics without the obscurants of an average of multiple genes. They use fluorescence recovery after photobleaching (FRAP), fluorescence correlation spectroscopy (FCS), fluorescence lifetime imaging (FLIM), and other imaging methods.
Biophysics Research: Studying DNA-Protein Interactions
Garini and his research team are studying variations in the mechanical conformations induced by the nucleoid-associated protein HU. They use two different approaches to detect variations in the dynamics and conformations of single DNA molecules due to HU binding.
The first approach, Tethered Particle Motion (TPM), allows them to detect the dynamic variations in the end-to-end distance of single DNA molecules due to the bending/unbending activity of HU. In their TPM setup, a small nanobead is attached to a linear dsDNA at one end, while the other end is attached to the surface. Illuminating the sample makes it possible to detect the scattered light from the gold nanobead. In addition, a higher signal-to-noise ratio is achieved using dark field illumination.
The bead diffuses in a restricted volume, which varies in the presence of a protein. In their second approach, they use an Atomic Force Microscope (AFM) to better understand the structural details of the HU-DNA complexes. They identify angle distributions for different concentrations and calculate the cumulative distribution function (CDF).
Protein Conformational Changes Studied at the Single Molecule Level
Garini’s group is also studying the link between conformational changes that a folded protein undergoes, and its functionality at high temporal resolution. The model molecule currently used for this study is the E. Coli Adenylate kinase; a multi-domain enzyme molecule.
Their research is performed at the single molecule level by applying different fluorescence techniques such as fluorescence resonance energy transfer (FRET) and FCS. This project is a collaboration with Prof. Elisha Haas' group.