Activation of calcium signaling is a universal response to stress that allows cells to quickly respond to environmental cues. Fluctuations in cytosolic calcium are decoded in plants by calcium-sensing proteins such as calcium-dependent protein kinases (CDPKs). The perception of microbes results in an influx of calcium that activates numerous CDPKs that propagate immune signals required for resistance against disease-causing pathogens. In this review, now published online in Molecular Plant-Microbe Interactions, Melissa Bredow and I describe our current understanding of CDPK activation and regulation, and provide a comprehensive overview of CDPK-mediated immune signaling through interaction with various substrates.
After a very successful thesis defence yesterday, Lauren is now the first MSc student to graduate from the Monaghan Lab. What a milestone! I am so proud of all of Lauren's many achievements and her now almost-complete thesis 'Analysis of E3 ligases and identification of ubiquitination sites regulating turnover of the plant immune signalling kinase BIK1'.
Lauren joined the lab in May 2016 as a summer student with an NSERC Undergraduate Summer Research Award, prior to starting as a MSc student that September. Her graduate work was supported by an NSERC Canada Graduate Scholarship and Michael Smith Foreign Study Supplement in her first year and an Ontario Graduate Scholarship in her second year. Lauren graduates as co-author of two publications, with another in the pipeline. Her work on identifying in vivo BIK1 ubiquitination sites, which she did during a 4-month stay abroad under the guidance of Frank Menke at the Sainsbury Lab, has advanced our research into BIK1 turnover and set the groundwork for additional thesis projects. In addition to working hard at the bench, Lauren also excelled in her coursework and organized the Molecular, Cell & Integrative Biology seminar series for our department for the last 2 years.
Lauren was accepted into the highly-competitive International PhD Rotation Programme at the John Innes Centre/Earlham Institute/Sainsbury Lab, in Norwich UK, and starts next week!
Congratulations Lauren, and best wishes during your PhD. The lab won't be the same without you!
Our short open-access paper ‘The jasmonate receptor COI1 is required for AtPep1-induced immune responses in Arabidopsis thaliana’ is now published in BMC Research Notes. This work stemmed from a curious observation made by first author Danalyn Holmes during her Honours thesis project. While performing other experiments that required use of the jasmonate receptor mutant coi1-16 as a control genotype, she was surprised to find that coi1-16 was specifically compromised in AtPep1-, but not flg22- or elf18-, triggered immune responses. Dependence of AtPep1-mediated signaling on jasmonate perception has been observed previously; her observations build on and corroborate these previous findings.
Danalyn had already moved to Germany to start her PhD when the article was accepted, so second author Lauren Grubb popped the champagne and we celebrated at the Grad Club via Skype. Congrats!
Melissa and Danalyn recently attended the annual IRTG International Plant Immunity Symposium at the Georg-August-Universität in Göttingen. Melissa gave a presentation about on-going work within the Monaghan Lab on Jacqueline's behalf, and Danalyn presented a poster on work she did during her time in our lab. IRTG 2171 PRoTECT is a collaborative program (that just received a $1.65M NSERC CREATE grant!) between the University of British Columbia and Georg-August-Universität, and this annual symposium allows members from groups within the program, among others, to highlight their work and showcase their efforts with their peers. There were many excellent posters and talks!
After spending the week in Göttingen, Melissa and Danalyn then travelled to Tübingen. Here, Melissa gave a seminar at the Universität Tübingen Centre for Molecular Biology of Plants, where Danalyn has just started her PhD within the Lahaye Group.
Danke und auf Wiedersehen!
Arabidopsis (Arabidopsis thaliana) AtBIK1 and rice (Oryza sativa) OsRLCK176 are orthologous receptor-like cytoplasmic kinases involved in plant immune signaling. In this Trends in Plant Science Spotlight article, I review several recent studies suggesting that proteasomal turnover of these kinases is regulated by orthologous group IV Ca2+-dependent protein kinases AtCPK28 and OsCPK4, revealing conserved interplay between phosphorylation and ubiquitination in immune homeostasis.
Read the original articles:
This month we bid farewell to several labmates. Danalyn joined the lab as a volunteer in early 2016 and continued as a BIOL540 research mentorship student, summer student, and Honours thesis student. She is starting her PhD with Thomas Lahaye at the ZMPB in Tuebingen Germany this summer. Alex began as a volunteer in the fall of 2016 and continued as a summer student and Honours thesis student, and plans to go to law school. Jennifer, who will soon graduate from the Biotechnology Advanced program at St Lawrence College, joined the lab in January of this year as a placement student. For the past months she has kept the lab in tip-top shape, helping everyone with various technical tasks. Cailun joined as a volunteer last summer, mainly working on making in-house DNA ladder using the pPSU vectors. She has recently taken up a position at PnuVax in Montreal. We are all so proud of everything these young scientists have achieved during their time in our group, and we look forward to seeing each of them flourish in their next positions. Farewell and keep in touch!
A capstone experience in the Queen's Biology undergraduate program is the Honours Thesis. This year, I had the pleasure of mentoring two extraordinarily talented young women - 4th-year students Danalyn Holmes and Alexandra Johnson Dingee. Both worked on deciphering the function of the Ca2+-dependent protein kinase CPK28 in Arabidopsis. We and others have shown that this kinase functions in both developmental and immune pathways. Danalyn used epistasis analysis to test if the proteins involved in CPK28-mediated immune signalling are also required for CPK28-mediated developmental signalling. Alex took a trans-complementation approach to test the role of phosphorylation in directing CPK28 function in the two pathways. Together, Danalyn and Alex have made significant contributions to our research program.
Both were recognized with Second Place prizes in the Cell & Molecular Biology section. Very well deserved - congrats on a job well done!