Exjobbsförslag från företag

Detta är ett uppsatsförslag hämtat från Nationella Exjobb-poolen. Klicka här för att komma tillbaka till samtliga exjobbsförslag.

Förslaget inkom 2004-10-19

Characterization of human thioredoxin-like 1 (Txl-1), a novel member of the thioredoxin family of redox proteins.

Thioredoxin (Trx) is a family of proteins that are conserved in all organisms from lower prokaryotes to human and function as general protein disulfide reductases. The redox activity of thioredoxins resides in the sequence of their conserved active site Cys-Gly-Pro-Cys (CGPC) which undergoes reversible oxidation of the two cysteine residues from a dithiol to a disulfide form. The maintenance of thioredoxin in its active reduced form is carried out by the flavoenzyme thioredoxin reductase (TrxR) at expense of the reducing power of NADPH, which forms the so-called thioredoxin system. Thioredoxins have been shown to regulate many different cellular processes such as apoptosis, transcription factor DNA binding activity, cell growth, differentiation and cancer or modulator of oxidative stress response.

During the recent years, our group has been engaged in the identification and characterization of novel members of the thioredoxin family of proteins. One of these proteins, named thioredoxin-like 1 (Txl-1), is characterized by the presence after the thioredoxin domain, of a C-terminal extension of 184 residues with no homology with any other protein in the databases. Txl-1 has been shown to be present in all human tissues screened and has a cytosolic localization. Despite having highly conserved orthologues in lower model eukaryotes such as the worm Caenorhabditis elegans or fruit fly Drosophila melanogaster there is no clue regarding its function.

This project aims to decipher the physiological role of Txl-1 in eukaryotic cells to provide relevant information about the significance of this protein in the general context of thioredoxins. With this purpose we will first purify specific polyclonal antibodies, which have been already produced. Once we have this tool in our hands we will screen the levels of Txl-1 in several human tissues by western blot analysis. Simultaneously, we will construct GFP fusion proteins to confirm and further characterize the cytosolic localization of Txl-1. A critical step of this project is the isolation and characterization of stable cell lines overexpressing Txl-1. This approach will allow us to study the role of txl-1 in normal cellular metabolism as well as in other pathological situations such as oxidative stress or apoptosis where other thioredoxins have been shown to play important functions.

Finally, and depending on the outcome of the previous strategies, we will initiate the characterization of the Txl-1 orthologue in the worm C. elegans in collaboration with Dr. Peter Swodoba´s group. The presence of Txl-1 in this lower eukaryote clearly supports the idea of a conserved function of Txl-1 and we intend to take advantage of the unique characteristics of this organism to study the biology of Txl-1 in humans.


Informationen om uppsatsförslag är hämtad från Nationella Exjobb-poolen.