לוח שנה משולב

Native mass spectrometry yields powerful insights into the structural and biochemical properties of proteins and protein complexes. To accelerate native MS studies, the Sharon lab developed the direct-MS method for analysis of proteins directly from crude lysates. I will discuss a general overview of the many applications enabled by direct-MS, with a particular focus on my work extending the technique to eukaryotic expression systems. By analyzing proteins directly from eukaryotic cell lysates, we can observe changes in ligand binding due to addition of cofactors or drugs to the media. We anticipate that this method will be broadly applicable to studies of eukaryotic post-translational modifications and protein stability as well as drug uptake and target engagement in eukaryotic cells.

The brain is rife with feedback connections within and between its regions, which almost inevitably should give rise to dynamic activity in the underlying neuronal populations. In the taste system of awake rats, neurons sequentially transition between activity states that correlate with taste perceptions such as identity, palatability, and novelty. In my talk I will present the current knowledge regarding taste information processing in the taste system and will add our recent description of sub-second novelty information transmission through a new circuit. Next, I will present unpublished data showing the dynamic changes in neuronal activity as taste memory is acquired and consolidated across 12 hours in behaving rats. Last, I will show how taste learning helps us investigating the early, pre-pathological, stages of Alzheimer’s disease.

Zoom link to join:
https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laUUdGbWR1VFJTdz09

Meeting ID: 966 0803 3618
Password: 564068

Host: Dr. Rita Schmidt rita.schmidt@weizmann.ac.il tel: 9070

The size, structural complexity, and functional perfection of proteins, raise a question for which we so far have no answer: How did the very first protein(s) evolve? Protein synthesis depends on dozens of highly sophisticated proteins thus presenting a chicken-egg dilemma. The most common explanation is that proteins emerged from short and simple polypeptides, that further expanded in length and complexity to give proteins as we know them today. Can we reconstruct such early polypeptide ancestors? Can a short polypeptide confer biochemical functions that are reminiscent of modern proteins? And can such polypeptides be evolutionary linked to their modern descents?
I will discuss our most recent findings with respect to the polypeptide precursors of nucleotide binding proteins, and the emergence of the first cationic amino acid.

The world around us is barely stable. To maintain constancy of perception, neuronal circuits adopt multiple mechanisms, each carefully tailored to grant the system with computational fidelity in the face of variable stimuli, yet to enable flexibility of computation in certain contexts. During my PhD I investigated the mechanisms that underlie retinal direction-selectivity. Using electrophysiology and modelling approaches, I will show how several mechanisms cooperate to maintain stability in the circuit’s response to moving objects carrying distinct characteristics. This stability is compromised when the retina is confronted by a repetitive light-adapting stimulus that changes the receptive field of cells in several layers of the circuit. Intriguingly, these changes in the cells’ receptive field expose antagonistic center-surround organization of direction coding: the center receptive field supports response to one direction, while the surround supports response to the opposite direction. Center-surround antagonism is thought to enhance spatial discrimination, but this is the first evidence for its contribution to retinal direction selectivity. This provides an example of how the retina elegantly implements computational motifs that are reminiscent of those found in higher brain regions, using just a handful of cell types, already at the first station of the visual system.

(If you are not from the neuroscience field, please check out THIS).

Zoom link to join:
https://weizmann.zoom.us/j/91058452206?pwd=UFpBZkVrM1luUSttSGZUTHRiNUg5dz09

Meeting ID: 910 5845 2206
Password: 229240