1. Review basic concepts and new development

2. Current methodologies and techniques

3. Reading scientific literature

4. Research processCollect background informationIdentify scientific questionsFind experimental approachesProcess and interpret dataDraw conclusions

5. Writing research proposals

Cell Biology I. Cellular structure and function

Cell Biology I. Topics

Cell membrane and organelles

Introduction of cell signaling

Membrane trafficking, secretory and endocytic pathways

Cytoskeleton

Cell cycle

Cell membrane

Wenxia:

1. The concept of cells

2. Prokaryotic cells, eukaryotic cells, mammalian cells

3. Cell membrane: plasma membrane and internal membrane

Wenxia:

1. The concept of cells

2. Prokaryotic cells, eukaryotic cells, mammalian cells

3. Cell membrane: plasma membrane and internal membrane

The bilayer structure of biomembranes

The faces of cellular membraneWenxia:

1. Exoplasmic and cytosolic face and its importance

2. Compartment with single and double bilayers

3. Different protein and lipid composition of different membranes

Wenxia:

1. Exoplasmic and cytosolic face and its importance

2. Compartment with single and double bilayers

3. Different protein and lipid composition of different membranes

Three major classes of membrane lipidsWenxia:

The relationship of the head group, fatty acid and lipid composition with the thickness, curve and fluidity of membrane

Wenxia:

The relationship of the head group, fatty acid and lipid composition with the thickness, curve and fluidity of membrane

Gel and fluid forms of the lipid bilayer

The fluid mosaic model of cell membrane

Initially proposed by Singer and Nicolson 1972

Proteins associated with the lipid bilayer

Glycophorin A E. coli Porin

Transmembrane proteins

adhesion moleculesglycosylphosphtidylinositol

Proteins with covalently linked lipid anchors

(a) Prenylation (b) Acylation

Ras Src

Proteins binds to lipids

Lipid rafts

By Susan Pierce, Nature Reviews Immunology 2, 96-105 (2002)

Lipid rafts

Atomic force microscopy

Fluorescence microscopy

Organelles of the eukaryotic cell

Fluorescence-activated cell sorter (FACS)

Dot plot of FACS

Purification of cell population by magnetic beads

Differential centrifugation is a common first step in fractionating a cell homogenate

Separation of subcellular organelle by equilibrium density gradient centrifugation

Fluorescence microscopy

Localization of the B cell antigen receptor in lipid rafts

Cholera toxin B subunitsAnti-BCR antibody

Deconvolution fluorescence microscopy

DNA/microtubules/actin filaments

Transmission electron microscopy

Scanning electron microscopy (SEM)

Journal discussion

Singer S. J. and Nicolson G. L. The fluid mosaic model of the structure of cell membrane. 1972. Science 175: 720.

Harder T., Scheiffele P., Verkade P. and Simons K. Lipid domain structure of the plasma membrane revealed by patching of membrane components. 1998. Journal of Cell Biology 141:929.