Research objectives and content
The endoplasmic reticulum (ER) is the most important quality control point in the exocytic pathway followed by newly synthesized secretory proteins. Those proteins that fail to achieve its mature conformation (due to defective folding and/or oligomerization) are selectively retained or degraded in the ER. This "ER-associated degradation" (ERAD) has been extensively studied for several proteins, and some functional general properties of the pathway have been described. However, little is known about the protein machinery involved in it.
The objective of the project is to analyze at the molecular level this degradative pathway, using as a model protein the light chain of the immunoglobulins. For this purpose our efforts will be directed towards the following studies: (1) To develop an "in vitro" model system for the light chain degradation. Microsomes from different yeast strains and from dog pancreas will be used. The first question will be if cytosol is required or not to the ERAD to occur. (2) To identify and characterize the protein machinery involved in degradation (located in the microsomes or in the cytosol). We are specially interested in the proteases catalyzing directly the degradation. In this sense, the participation of the proteasome in the ERAD will be assessed.
Training content (objective, benefit and expected impact)
The main objective is to obtain a detailed knowledge at the molecular level of the novel degradative pathway of proteins m the ER. This will have special relevance in three aspects: basic research, health care and biotechnology. Concerning the first, the ERAD may be a constitutive pathway of degradation very important in the control of the level of secretory proteins in the cells, and probably, it is finely regulated to ensure this. Regarding the second, many genetic disorders involve a defect of the protein that implies its ER-associated degradation.. So, knowing this pathway may provide new tools for therapy. Finally, about the third point, the production of many secreted polypeptides of industry and medical interest should be improved by regulating the ERAD in the cell system that produces such proteins. This could only be done if this pathway is well-known at the molecular level.
Links with industry / industrial relevance (22)