MHC class II associated invariant chain (Ii) or CD74 (Cluster of Differentiation 74) is a protein essential for proper formation and trafficking of MHC class II to the antigen loading compartment and thus efficient antigen presentation. Ii induces a delay in endosomal maturation and an enlargement of early endosomes dependent on its cytoplasmic domain. This function is independent of the normal early endosomal fusion machinery comprising the small GTPase Rab5, PI3 kinase and the tethering factor EEA1.
All membrane fusion events in eukaryotic cells are mediated by SNARE (soluble NSF attachment protein receptor) proteins. Four different SNARE-domains (Qa, Qb, Qc and R) are needed to form a functional complex. We have recently performed an siRNA screen to identify SNAREs and SNARE-regulating proteins involved in Ii-induced endosome enlargement
The aim of this master project is to characterize the specific SNARE complex in Ii-positive endosomes and its functional significance in antigen presentation. The master student will study the localization and interaction of SNARE proteins by immunofluorescence, expression of fluorescent protein-tagged SNARE proteins and confocal microscopy, depletion of target proteins by small interfering RNA, and antigen presentation assays.
Methods:
The project will take place in the group of Oddmund Bakke who is also head of the NorMIC Oslo imaging platform. The student will the in particular learn several state-of-the-art microscopy techniques image processing and quantitative image analysis that are very much in demand in many disciplines in Norway and abroad.
The project will also involve additional techniques of molecular biology and cell biology, including mammalian cell culture, gene manipulations, protein expression and purification, and immunoprecipitation +++ and is particularly suited for a motivated candidate that have a wish to continue working with cellular/molecular research and imaging.
Please contact
Dominik Frei or Oddmund Bakke, 3rd floor IBV, or contact by email d.m.frei@ibv.uio.no
or oddmund.bakker@ibv.uio.no (phone 22855787 or 95851479)