INTRO TO MEDI 501

There is no text book. For additional background reading, Molecular Biology of the Cell (Alberts et al), or other advanced Molecular/Cell Biology texts will be helpful. You should not have to purchase a new copy as there should be plenty of these available in your labs or as used texts.

Kimball’s Biology Pages,http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/ is a good online Biology text – for general background reading, but some material not completely up to date.

Duronio - September 12 - Signalling domains regulating signalling pathways Signal transduction events will be summarized, starting with an overview of receptor structures and receptor families. Basic concepts in signal transduction will be reviewed, emphasizing G protein-mediated signals and signals mediated by receptors acting via tyrosine kinases. Regulation of protein function by phosphorylation and dephosphorylation and the importance of protein-protein interactions mediated by specific domains will be emphasized. While impossible to cover in a single lecture, this is intended to give only some highlights of key questions in this field.

Objectives of lecture 1

• Recognize the different types of receptors and the mechanisms they use to signal into cells

• Understand the importance of signal amplification

• Understand the basic mechanisms of protein phosphorylation and the type of kinases

• Identify some of the key protein interaction domains that function in signalling pathways

• Be aware of applicability of these studies to virtually all disease processes (cancer is highlighted)

Duronio - September 24 - Apoptosis – Regulation of cell death and survival  One of the 'hot' topics in cell biology and in the study of cell growth regulation is the understanding that the control of cell death plays a major role in many aspects of development, and in many diseases. The basic mechanisms regulating the activation of the 'executioner' caspases are currently understood in great detail. The complexities of caspases, BCL-2 family members, and death receptors that make up the machinery controlling apoptosis in higher animals will be reviewed.

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Objectives of Lecture 2

• Being able to distinguish apoptosis from necrosis and describe key features

• Understand the role of BCL-2 family, caspases and death receptors

• How to assay for apoptosis using various approaches

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Some important concepts to review…

A Typical Animal Cell

20-30,000Genes

10-20,000 Distinct Proteins

A Typical Cell: A Complex Network of Signalling Events

As many as 5,000 of theProteins used for Signalling

Many of these Expressed below Detectable Levels

Many have not yet been functionally characterized

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Motifs, Domains, Homology and Consensus

-what does the terminology mean?

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Motifs, Domains, Homology and Consensus

e.g. in Cytokine Receptors:-Extracellular and intracellular domains of protein structure

- conserved Cysteines foundregularly spaced and impart specific 3D structure

-WSXWS ‘motif’ universally present - like a ‘signature’

Members of BCL-2 familyCharacterized by their ‘BCL-2 Homology’ Domains

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Homology refers to ‘Similarity’ of the sequences being compared

Consensus refers to the most common amino acids (nucleotides) within a given sequence

Alignment of the BH3 domains of the proapoptotic Bcl-2 family members from mouse and C. elegans.

Bouillet P , Strasser A J Cell Sci 2002;115:1567-1574

©2002 by The Company of Biologists Ltd

REFERENCES – Signal transduction (Duronio, lecture 1)

The Ins and Outs of Signalling. J. Downward. Nature 411: 759 - 762 (2001).

Kinome signaling through regulated protein-protein interactions in normal and cancer cells. T. Pawson and M. Kofler. Curr Opinion Cell Biol 21: 147-53 (2009).

Protein phosphorylation in signaling - 50 years and counting. T. Pawson and J. Scott. TIBS 30: 286-290 (2005).

Cell signaling by receptor tyrosine kinases. M.A. Lemmon and J. Schlessinger. Cell 141: 1117- 1134 (2010).

V. Duronio, The Life of a Cell – Apoptosis Regulation by the PI3K/PKB Pathway. Biochem J. 415: 333-344 (2008).

For further in depth study: STKE, Science website http://stke.sciencemag.org/

References – Apoptosis (Duronio lecture 2)

Leber, B, Lin, J and Andrews, DW. Embedded together: The life and death consequences of the Bcl-2 family with membranes. Apoptosis 12, 897-911 (2007).

Danial, NN and Korsmeyer,SJ. Cell death: critical conrol points. Cell 116, 205-219 (2004).

F. Toledo and G.M. Wahl, Regulating the p53 pathway. Nature Rev. Cancer 6: 909-23 (2006).

Chipuk et al., BCL-2 Family Reunion. Molecular Cell 37: 299-310 (2010)

Duronio, V. The life of a cell: apoptosis regulation by the PI3K/PKB pathway. Biochem. J. 415: 333-344 (2008).

Flow cytometry tutorial: http://probes.invitrogen.com/resources/education/tutorials/4Intro_Flow/player.html