BIO SEMINAR:Molecular organization of phase-separated membraneless...

Speaker: Uygar Tazebay

Title: Molecular organization of phase-separated membraneless organelles in health and disease

Date/Time: 17 May 2021 / 12:40 - 13:40

Zoom: Meeting ID: https://sabanciuniv.zoom.us/j/7260077994 

Abstract: Eukaryotic cells organize their intracellular components into organelles that can be either membrane-bound or membraneless. A large number of membraneless organelles, including nucleoli, nuclear speckles, P-bodies, and stress granules, exist as liquid droplets within the cell and arise from the condensation of cellular material in a process termed liquid-liquid phase-separation (LLPS). Membraneless subcellular compartments have been shown to form by phase-separation of intrinsically disordered proteins and RNA, but molecular mechanisms regulating their formation and disassembly, as well as their cellular significances were not fully understood. Coiled-coil domain-containing protein-124 (Ccdc124) is a conserved eukaryote protein associated with membraneless biomolecular complexes that were involved in propagation of cell division and translational recovery. Computational analyses classify Ccdc124 as a disordered RNA-binding protein having polyampholyte characteristics typical for proteins in phase-separated organelles. To better understand the cellular role of Ccdc124, we identified interaction partners of Ccdc124 by combining state-of-the-art proteomics methods, such as affinity purification/SILAC quantitative mass-spectrometry and in vivo proximity-dependent biotinylation (BioID) based proteomics. In addition to its previously identified centrosome, midbody, or ribosome interactions, we found that Ccdc124 was also associated with major RNA-binding proteins involved in RNA metabolism and intracellular immunity. Our goal is to better understand functional and mechanistic basis of how cells exploit the phase-separation process for adaptive cellular modalities in normal physiology, and how it is impaired in disease, with a particular focus on a neurodegenerative disorder known as the ALS disease.

Bio: Uygar Tazebay graduated from the Middle East Tech University Biological Sciences Department in 1993. He carried out his Masters and PhD studies at the University of Paris-11 on transcriptional regulation of genes in eukaryote models.  After obtaining his PhD in 1998, he went to New York, Albert Einstein College of Medicine for his post-doctoral studies where he identified the human mammary gland transport system, and studied regulation of iodide uptake in healthy mammary gland, and in breast cancers in humans. He is the holder of a patent entitled "diagnosis and treatment of breast cancer". On his return to Turkey, he established his lab at Bilkent University MBG Department in 2001, and continued his research on gene regulation of mammary gland iodide transport, and later developed a laboratory working on functional genomics. In 2013 he moved to Gebze Institute of Technology, Department of MBG, and established a cell biology laboratory focusing on formation and regulation of membraneless organelles in eukaryotes. He established Gebze Technical University Centre Research Laboratory, and Animal Research Facility in 2016, and he is currently the Director of this research complex. Besides he acted as a Chairperson at Gebze MBG between 2017-2020.