Research group

Name: Goodpasture antigen-binding protein (GPBP)

Principal Investigator: Dr. Juan Saus Mas

Research Group Activity

The discovery of the Goodpasture (auto)antigen as the α3(IV)NC1 domain and GPBP as the protein kinase that phosphorylates its divergent N terminal region have been associated with the onset and development of our research group.

Since we observed that GPBP is overexpressed in patients undergoing Goodpasture's disease (Goodpasture patients) and in patients with other autoimmune disorders, all of our research has been directed to characterize GPBP biology and its interaction with the α3(IV)NC1 domain, in an attempt to understand the autoimmune pathogenesis and to generate specific tools for the clinical setting.

In this regard, in the last five years we have shown that:

1) GPBP regulates the folding of the α3(IV)NC1 domain and collagen network organization in the GBM, a principal component of the glomerular filtration barrier.

2) The production of autoantibodies in Goodpasture's disease is a legitimate reaction of the immune system against aberrant conformations of the α3(IV)NC1 domain which disturb the collagen network of the GBM.

3) GPBP is a circulating protein whose increased expression induces Goodpasture disease but also immune complex-mediated glomerulonephritis such as IgA nephropathy and renal lupus.

4) TNF-α, a pro-autoimmune and pro-inflammatory cytokine regulates GPBP expression and activity.

5) The GPBP recognition site at the N terminal region of the α3(IV)NC1 domain represents a major anchoring site for the epithelial cell (podocyte) at the glomerular filtration barrier.

6) GPBP plays a pivotal role in the development of striated muscle and central nervous system in inferior vertebrates.

7) GPBP along with a novel structural protein family named GPBP-interacting proteins (GIP), directs the myofibrilar organization in mammalians, unveiling that GPBP regulates supramolecular assembly of structural proteins at both intracellular and extracellular compartments.

8) GPBP phosphorylates myelin basic protein, a well-known autoantigen in multiple sclerosis.

These results have been gathered into various international patents, PhD thesis and research reports. To bring our findings into clinical setting in addition to file patents we have founded Fibrostatin SL, a biotech company devoted to exploit our patents and to develop new products for the diagnosis and therapy.