Paul Cullen’s Lectures for BIO402/502Office hours: Friday 2PM or by appointment

pjcullen@buffalo.edu

Test will be on October 29th 7PM-9PMShort answer, medium answer, and essay.

Primarily from the lectures, with the book as a backup.

Section II Protein Secretion, Trafficking & Degradation; Signal Transduction; Cytoskeleton & Cell Motility; Extracellular Matrix & Cell-Cell Interactions Dr. Cullen (12 lectures, September 25th - October 23rd) Protein Delivery to the ER, Golgi, Exocytosis (Cullen; 1 lect, Sept. 25th) CHAPTER 12 Alberts Protein Glycosylation and unfolding (Cullen; 1 lect, Sept. 30th) CHAPTER 13 Alberts Golgi, Snares, COPs and Arfs (Cullen; 1 lect. Oct. 2th) CHAPTER 13 Alberts PI Signaling and Vesicle Identity (Cullen; 1 lect, Oct. 5th) CHAPTER 13 Alberts Protein Targeting: Peroxisome/Mitochondria (Cullen; 1 lect, Oct. 7th) CHAPTER 12 Alberts Cell Polarity - Actin Cytoskeleton (Cullen; 1 lect, Oct. 9th) CHAPTER 16 Alberts Cell Polarity - Microtubules (Cullen; 1 lect, Oct. 12th) CHAPTER 16 Alberts Origins of Cell Adhesion (Cullen; 1 lect, Oct. 14th) CHAPTER 19 Alberts Cell Adhesion Molecules, Integrins and Mucins (Cullen; 1 lect, Oct. 16th) CHAPTER 19 Alberts The Extracellular Matrix (Cullen; 1 lect, Oct. 19th) CHAPTER 19 Alberts Cell Polarity Regulation and Signal Transduction (Cullen; 1 lect, Oct. 21st) CHAPTER 15 Alberts Genomics Approaches to Cell Biology (Cullen; 1 lect, Oct. 23rd) HANDOUTS Exam 2 (Proctor: Berezney, October, 29st)

Exocytosis: Delivery of Secretiory Vesicles to the Cell SufaceRetrograde Transport: Delivery of Vesicles to Internal Compartments

HIV enters through membrane fusionInfluenza enters through receptor-mediated endocytosis

Snare-like

IM-likeProteinsHydrophobicTails exposed

PhagocytosisSpecialized form of receptor-mediated endocytosisMacrophages (white blood cells) Food (in microorganisms), dead cells (1011 red blood cells/day), glass,Latex beads, asbestos fibers, and antigens, but not other live cells

Temporal Order of Clathrin-Mediated Endocytic Intermediates

PI(4,5)P2

PIPK-

Recruitment of Clathrin Assembly Factors

AP-2*AP180A,B*Eps15Clathrin

Hip1R*Epsin*

MembraneCurvature

Amphiphysin2*Endophilin

Membrane Restriction/FissionVesicle Release

Dynamin*Actin

polymerization

PI(4,5)P2-binding Proteins*PI(4,5)P2

Conner and Schmid, Nature 2003

Transcytosis from the Basolateral membrane To the Apical Membrane Allows passage of materials Across cellular boundaries

Antibodies must also transverse the intestine of the infant

acidic

neutral

Figure 12-6 Molecular Biology of the Cell (© Garland Science 2008)

Figure 12-21a Molecular Biology of the Cell (© Garland Science 2008) Some Proteins made in the mito.

Figure 12-22 Molecular Biology of the Cell (© Garland Science 2008)

The Mitochondrial Import Sequence is an amphipathic alpha helix

Figure 12-23 Molecular Biology of the Cell (© Garland Science 2008)

TOM = cytosolic proteins to the intermembrane spaceTIM = cytosolic proteins to the matrix and inner membraneOXA = mitochondrially produced proteins to the intermembrane space

Figure 12-24 Molecular Biology of the Cell (© Garland Science 2008)

An in vitro experiment to determine how mitochondrial transport occurs

Figure 12-25 Molecular Biology of the Cell (© Garland Science 2008)

Cytosolic chaperones like Hsp70 keep proteinsUnfolded until they are fed into the mitochondriaAnd they contribute to the import process.

The RTG Network: a signaling pathway from the mitochondria to theNucleus.

Mitochondrial retrograde signaling is a pathway of communication from mitochondria to the nucleus under normal and pathophysiological conditions. The best understood of such pathways is retrograde signaling in the budding yeast Saccharomyces cerevisiae. It involves multiple factors that sense and transmit mitochondrial signals to effect changes in nuclear gene expression; these changes lead to a reconfiguration of metabolism to accommodate cells to defects in mitochondria. Analysis of regulatory factors has provided us with a mechanistic view of regulation of retrograde signaling. Here we review advances in the yeast retrograde signaling pathway and highlight its regulatory factors and regulatory mechanisms, its physiological functions, and its connection to nutrient sensing, TOR signaling, and aging.

Aging, the greatest disease of all!

http://www.ucsf.edu/science-cafe/conversations/kenyon/

Like many young scientists with a novel idea, Kenyon encountered more skepticism than support in the early 1990s. Indeed, one fellow scientist, worried that she had gone “over the edge,” warned that if she continued to insist that aging was subject to genetic regulation, she would soon fall off the Earth altogether. But her world turned out to be round, not flat. And now firmly anchored as, if not exactly the “queen of aging research,” then certainly its ace, Kenyon commands no fewer than 386,000 entries on a standard Google search.

The story is now well-known. One of Kenyon’s lab rotation students — Ramon Tabtiang — in one of his very first experiments, picked a needle out of the haystack that is the C. elegans genome. In short, he found a mutant gene, dubbed daf-2, that made worms live twice as long.