Royal Netherlands Institute for Sea Research

Alexander Westbye

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Research interests and expertise

Postdoctoral researcher studying archaeal lipid production. Members of the Archaea (prokaryotes) have fundamentally different membrane lipids compared to life's other two domains (the Bacteria and Eukarya). The biosynthesis of several archaeal membrane lipids is still poorly understood, particularly the later steps. Using bioinformatic analysis, cultivation of model archaeal species, stable isotope probing and heterologous protein production I aim to gain new insight into the molecular details of archaeal membrane lipid production.


Previous research 
I previously worked extensively on regulation of horizontal gene transfer in Alphaproteobacteria. Several members of this bacterial group, particularly the Rhodobacteracea produce gene transfer agents (GTAs). GTAs are small bacteriophage-like particles that appear to have evolved into vectors for horizontal gene transfer and are produced by a subset of the cell population. For my PhD, I characterized the genetic regulation of the GTA produced by the model organisms Rhodobacter capsulatus, a purple non-sulfur bacterium. Using targeted chromosomal mutations, transposon screens, promoter activity measurements and biochemical methods I found that this GTA is released by regulated cell lysis and discovered the genetic basis of the GTA head spikes and demonstrated that the spikes mediate binding to a capsular receptor.  The conserved phosphorelay CckA-ChpT-CtrA is a central regulator of GTA production, and I found that phosphorylation of CtrA is essential for maturation of GTA particles, cell lysis and head spike production. 

Education and other scientific experience
PhD: Microbiology & Immunology, The University of British Columbia (Canada) - awarded 2016.
BSc: Biochemistry, The University of Oslo (Norway) - awarded 2008.
Norwegian Defence Research Establishment (research assistant) - 2008/09.
GE Healthcare, Dept. Chemical Development (Norway; trainee) - 2004/05.
The University of Tromsø (Norway; pharmacology and cell biology courses) - 2008.

Scientific articles (peer reviewed):

Westbye AB, O'Neill Z, Schellenberg-Beaver T, Beatty JT (2017) The Rhodobacter capsulatus gene transfer agent is induced by nutrient depletion and the RNAP omega subunit. Microbiology. 2017 Sept 4; 163:1355-1363

Lang AS, Westbye AB, Beatty JT (2017) The distribution, evolution, and roles of gene transfer agents in prokaryotic genetic exchange. Annu Rev Virol. 2017 4:22.1-22.18

Westbye AB, Beatty JT, Lang AS (2017) Guaranteeing a captive audience: coordinated regulation of gene transfer agent (GTA) production and recipient capability by cellular regulators. Curr Opin Microbiol. 2017 Jun 6;38:122-129.

Westbye AB, Kuchinski K, Yip CK, Beatty JT (2016) The Gene Transfer Agent RcGTA Contains Head Spikes Needed for Binding to the Rhodobacter capsulatus Polysaccharide Cell Capsule. J Mol Biol. 2016 Jan 29;428(2 Pt B):477-91.

Kuchinski KS, Brimacombe CA, Westbye AB, Ding H, Beatty JT (2016) The SOS Response Master Regulator LexA Regulates the Gene Transfer Agent of Rhodobacter capsulatus and Represses Transcription of the Signal Transduction Protein CckA. J Bacteriol. 2016 Feb 1;198(7):1137-48.

Peña-Castillo L, Mercer RG, Gurinovich A, Callister SJ, Wright AT, Westbye AB, Beatty JT, Lang AS (2014) Gene co-expression network analysis in Rhodobacter capsulatus and application to comparative expression analysis of Rhodobacter sphaeroides. BMC Genomics. 2014 Aug 28;15:730.

Westbye AB, Leung MM, Florizone SM, Taylor TA, Johnson JA, Fogg PC, Beatty JT (2013) Phosphate concentration and the putative sensor kinase protein CckA modulate cell lysis and release of the Rhodobacter capsulatus gene transfer agent. J Bacteriol. 2013 Nov;195(22):5025-40.

Fogg PC, Westbye AB, Beatty JT (2012) One for all or all for one: heterogeneous expression and host cell lysis are key to gene transfer agent activity in Rhodobacter capsulatus. PLoS One. 2012;7(8):e43772.

Other scientific publications

Westbye AB, Fogg PC, Beatty JT (2014). Endolysin Expression, Purification and Activity Determination by Zymography. Bio-protocol 4(16): e1208.