Institute seminar January 20th 10.30 Harald Stenmark

H. Stenmark
H. Stenmark

The institute seminar on Wednesday January 20th will be held by Harald Stenmark from the Department of Biochemistry.

Title of his talk: "A lipid kinase complex and its role in tumour suppression"

The seminar will be in Auditorium in the New Research Building at Montebello and starts at 10:30.

A lipid kinase complex and its role in tumour suppression


Phosphorylated derivatives of the membrane lipid phosphatidylinositol (PtdIns), known as phosphoinositides, regulate membrane-proximal cellular processes by recruiting specific protein effectors involved in cell signalling, membrane trafficking and cytoskeletal dynamics. Two phosphoinositides that are generated through the activities of distinct phosphoinositide 3-kinases (PI3Ks) are of special interest in cancer research. PtdIns(3,4,5)P3, generated by class I PI3Ks, functions as tumour promotors by recruiting effectors involved in cell survival, proliferation, growth and motility. Conversely, there is evidence that PtdIns(3)P, generated by class III PI3K, functions in tumour suppression. Three subunits of the class III PI3K complex (Beclin 1, UVRAG and Bif1) have been independently identified as tumour suppressors, and their mechanism of action in this context has been proposed to entail activation of autophagy, a catabolic pathway that is thought to function tumour suppressive by scavenging damaged organelles that would otherwise produce reactive oxygen species that cause DNA instability. We have recently obtained evidence for three additional functions of PtdIns(3)P that might contribute to its tumour suppressors activity. One such mechanism involves ligand-mediated downregulation of growth factor receptors mediated by the endosomal sorting complex required for transport (ESCRT) machinery. Another potential tumour suppressor mechanism of PtdIns(3)P is mediated by its participation in signalling pathways. The third and most recent tumour suppressor mechanism involves the regulation of cytokinesis, the final stage of cell division. Elucidation of the mechanisms of tumour suppression mediated by class III PI3K and PtdIns(3)P will identify novel Achilles heals of the cell’s defence against tumourigenesis and will be useful in the search for prognostic and diagnostic biomarkers in cancer.


Harald Stenmark's group - Intracellular communication

Department of Biochemistry

Institute seminar list, spring semester 2010

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