Ragna Rönnholm - Biochemistry and Biotechnology

Characterization of the novel Golgi proteins GP49 and GP69

Ragna Rönnholm, PhD, University lecturer

The Golgi complex, the intermediate compartment included, plays a central role in intracellular membrane trafficking.It receives newly synthesized proteins from the ER, modifies sequentally their oligosaccharides, and sorts them to their final cellular destinations. At the same time it receives material entering the cell by endocytosis. Importantly, the incoming and outgoing membrane pool has to be in balance, which is guaranteed by the dynamic behaviour of the Golgi membranes.

The Golgi complex is involved in cell motility,cell polarization and differentation, as well as mitosis and apoptosis, and recent data shows that the Golgi membranes also play an important role as a platform for intracellular signalling.
A rough estimation is that some 1000 Golgi proteins are orchestrating all these functions of this organelle as well as the membrane trafficking between the ER and the Golgi.

By a protemic approach using cellfractionation and Multidimensional Protein Identification Technology we have been able to identify  novel Golgi specific proteins which we have named GP49 and GP69. These proteins are currently beeing characterized by a variety of methods including siRNA -technology,immunofluorescence microscopy, microinjection, transport assays and structural biochemistry. Only by identifying and characterizing all Golgi proteins we can start to build up a holistic picture of the Golgi complex functions.

Contact: ragna.ronnholm(at)helsinki.fi
Tel: +358 (0)9 191 59024