The LonB protease modulates the degradation of CetZ1 involved in rod-shape determination in Haloferax volcanii

The Archaeal Proteome Project advances knowledge about archaeal cell biology through comprehensive proteomics

“…Multiplex quantitative stable isotope labeling in cell culture (SILAC) was used to monitor the changes in the H. volcanii proteome during hypochlorite stress. A double auxotroph for lysine and arginine (LM08) was generated and used to fully incorporate the heavy amino acids 13 C/ 15 N-lysine (+8 Da) and 13 Carginine (+6 Da) into each peptide. Cells were grown in GMM supplemented with the heavy vs. light amino acids (0.3 mM each).…”

“…Another important aspect of cell surface homeostasis are membrane-associated proteases like LonB and rhomboid protease RhoII. The former is involved in the regulation of cell shape and carotenoid biosynthesis in H. volcanii while a knockout of the latter affected the N-glycosylation of the S-layer glycoprotein with a sulfoquinovose-containing oligosaccharide 4,5,7,13,49 . The datasets PXD007061/PXD013046 and PXD011218 originally characterized the proteomes of a conditional LonB mutant and a RhoII knockout mutant, respectively.…”

“…Yet, our understanding of archaeal cell biology is lacking behind eukaryotes and bacteria. Recently, the importance of proteomics as a tool for addressing specific biological questions in archaea has become readily apparent [3][4][5][6][7][8][9][10][11][12][13] . However, such limited analyses typically leave valuable information buried in the raw data.…”

Proteolysis at the Archaeal Membrane: Advances on the Biological Function and Natural Targets of Membrane-Localized Proteases in Haloferax volcanii

“…Consistent with these phenotypes, high resolution proteomics showed that the abundance and/or turnover of several tubulin homologues were modified depending on LonB expression (Cerletti et al, 2015(Cerletti et al, , 2018. Specifically, the archaeal rod-shape determinant CetZ1 was degraded faster when LonB expression was incremented, which was substantiated by an in vivo degradation assay (Ferrari et al, 2020). Under reduced LonB levels CetZ1 was still degraded suggesting that the turnover of this protein may rely on the activity of other protease/s in addition to LonB.…”

“…This change in morphology is directed by the tubulin-like protein CetZ1 (HVO_2204) (Duggin et al, 2015). Interestingly, H. volcanii mutant cells containing reduced LonB amounts growing in liquid cultures showed unusually irregular-elongated cells compared to the parental strain H26 (Cerletti et al, 2014) while swarmer cells induced to overexpress LonB evidenced a rounded-shaped morphology (Ferrari et al, 2020). Consistent with these phenotypes, high resolution proteomics showed that the abundance and/or turnover of several tubulin homologues were modified depending on LonB expression (Cerletti et al, 2015(Cerletti et al, , 2018.…”