Cytoskeletal Motor Proteins: Part 3: Mining the Genome for Mitotic Treasures (33:41)

submitted by: scivee-team
The third (last) part of the lecture is on mitosis, the process by which chromosomes are aligned and then segregated during cell division. I will describe our efforts to find new proteins that are important for mitosis through a high throughput RNAi screen. I will discuss how we technically executed the screen and then focus on new proteins that are we discovered that are involved in generating the microtubules that compose the mitotic spindle. I also discuss the medical importance of...

Cytoskeletal Motor Proteins: Part 2: Single Molecule Approaches for Understanding Molecular Motors (25:20)

submitted by: scivee-team

In the second part of this lecture, I will discuss our laboratories current work on the mechanism of movement by dynein, a motor protein about which we still know very little. This is a research story in progress, where some advances have been made. However, much remains to be done in order to understand how this motor works.

Cell Organization & Cell Motility: Part 3: Principles of Cellular Organization: The Universal Cytoskeleton (29:17)

submitted by: scivee-team
In the third part, I discuss how the complex shapes of cells are created by the cytoskeleton, and I compare and contrast prokaryotes (which have actin-, tubulin-, and intermediate filament -like proteins) and eukaryotes in this regard. In particular, I speculate that cytoskeletal dynamics were necessary to evolve simple bacterial shapes and cell division, but that additional layers of complexity (namely regulated nucleation and molecular motors) allowed eukaryotes to evolve more complex...

Cell Organization & Cell Motility: Part 2: Force Generation by Actin Assembly: Theories and Experiments (46:16)

submitted by: scivee-team

The second part is devoted to understanding how the polymerization of actin can produce, which is a current area of research in our laboratory. Here, I cover theories for how polymerization might be used to produce forces, and our efforts to test these models using optical traps, atomic force microscopes, and nanofabricated devices.

Cell-Cell Communication in Bacteria by Bonnie Bassler, June 2008 - Part 1: Bacterial Quorum Sensing: Intra- and Inter-Species Communication (53:48)

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Bacteria, primitive single-celled organisms, communicate with chemical languages that allow them to synchronize their behavior and thereby act as enormous multi-cellular organisms. This process is called quorum sensing and it enables bacteria to successfully infect and cause disease in plants, animals, and humans. Investigations of the molecular mechanisms underlying quorum sensing are leading to the development of novel strategies to interfere with quorum sensing. These strategies form the...

Cell Organization & Cell Motility by Julie Theriot - Part 1: Cell Motility and the Cytoskeleton: Protein Polymers Crawling Cells and Comet Tails (43:53)

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This lecture covers the biochemical basis of actin-based motility (focusing on the pathogen Listeria as a model system for this process), the biophysical mechanism of polymerization-based force generation, and an evolutionary perspective of cell shape in prokaryotes and eukaryotes. The first part covers our understanding of how cells use the actin cytoskeleton to crawl. The pathogenic bacteria Listeria (which causes food poisoning) uses the actin cytoskeleton to propel itself in the...

Protein Secretion and Vesicle Traffic by Randy Schekman - Part 1: Genetic Dissection of the Secretory Pathway (36:35)

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Protein secretion is executed by a cellular pathway involving the delivery of membrane and soluble secretory proteins in vesicles that capture newly-synthesized proteins assembled in the endoplasmic reticulum (ER) and sorted in the Golgi apparatus. Vesicles fuse with the plasma membrane resulting in the discharge of soluble molecules to the cell exterior and integration of vesicle membrane proteins and lipids in the cell surface. Baker's yeast cells grow by vesicle fusion and secretion at...

Growth Control in Animal Development by Martin Raff- Part 1: Cell Size Control (40:56)

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The size of an organ or organism depends mainly on the sizes and numbers of the cells it contains. In the first segment of my talk, I describe our work on cell size control in cultures of purified rat Schwann cells. Most proliferating cells grow before they divide, but it is not known how growth and division are coordinated to ensure that cells divide at an appropriate size. We have found that extracellular signals can control cell growth and cell-cycle progression separately and that the...