Validation and characterisation of a micro-protein in Campylobacter jejuni
Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
The Epsilonproteobacterium Campylobacter jejuni is a major foodborne pathogen in humans mainly causing gastroenteritis, and is connected to several secondary autoimmune diseases. A large part of the small genome of C. jejuni is still to be characterized, with many hypothetical proteins present. Micro-proteins - those that are < 50 amino acids and encoded by a small open-reading frame (micro-ORF) - are an understudied class of proteins that have been shown to be involved in vital processes in the cell, such as cell division, modulation of enzymatic activities, and stress responses. So far, few examples of micro-proteins are known in pathogenic bacteria, and fewer are known that affect virulence. In this study, we provide first evidence that the conserved micro-ORF Cj0878 of C. jejuni is translated by showing that a GFP translational fusion to the ORF is translated, and that Cj0878 mRNA and protein levels are affected by the absence of iron in minimal media. With in silico analysis we found that Cj0878 is likely a highly basic protein and may have an amphipathic nature. We also show that a predicted base-pairing interaction between Cj0878 mRNA and the sRNA CJnc170 likely has a regulatory consequence, by showing that CJnc170 mutant strains have different levels of the Cj0878 translational fusion protein. To summarise this study provides the first validation and characterisation of a micro-protein in the important pathogen C. jejuni, and provides the basis for future studies on the function of the protein.
Place, publisher, year, edition, pages
UPTEC X, 17 004
Natural Sciences Engineering and Technology
IdentifiersURN: urn:nbn:se:uu:diva-316733OAI: oai:DiVA.org:uu-316733DiVA: diva2:1078854
Molecular Biotechnology Engineering Programme
Sharma, Cynthia, Prof. Dr.Svensson, Sarah, Dr.
Andersson, Jan, UnversitetslektorWagner, Gerhart, Prof. Dr.