The synthesis and role of Trypanosoma brucei ZC3H11 during the heat shock response

• Applicant: Professorin Dr. Christine Elizabeth Clayton
• Subject Area: Parasitology and Biology of Tropical Infectious Disease Pathogens ; Cell Biology
• Term: from 2012 to 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 218732757

• Final Report Year: 2019

Final Report Abstract

We had two main questions: A. How is expression of ZC3H11 regulated in procyclic forms? How is ZC3H11 mRNA translation repressed at 27*C? How is ZC3H11 mRNA translation enhanced at 39*C? How is ZC3H11 proteolysis controlled? B. How does ZC3H11 act during the procyclic heat shock response? Is the mechanism the same as in bloodstream forms at 37°C (MKT1, PBP1, LSM12)? If not, which other interactions are required? For (A), we mapped the regulatory element in great detail. We found that phosphorylation (probably by casein kinase 1.2) influences ZC3H11 degradation, which is reduced by proteasome inhibitors. Various different attempts to identify proteins required for ZC3H11 regulation were, however, unsuccessful. For (B) we took advantage of a new method and showed that mRNAs that are bound by ZC3H11 are preferentially excluded from translationally inactive RNA-protein granules that form after heat shock. Studies of proteins that activate expression in the tethering assay revealed an additional component of the MKT1-PBP1-LSM12 complex (XAC1) and a second homologue of Mkt1, MKT1L.

Publications

• (2016) Regulating a post-transcriptional regulator: protein phosphorylation, degradation and translational blockage in control of the trypanosome stress-response RNA-binding protein ZC3H11. PLoS Pathogens 12:e1005514
  Minia I, Clayton C
  (See online at https://doi.org/10.1371/journal.ppat.1005514)
• (2016) Translation regulation and RNA granule formation after heat shock of procyclic form Trypanosoma brucei: many heat-induced mRNAs are increased during differentiation to mammalian-infective forms. PLoS Negl Trop Dis 10:e0004982
  Minia I, Merce C, Terrao M, Clayton C
  (See online at https://doi.org/10.1371/journal.pntd.0004982)
• (2018) Stress susceptibility in Trypanosoma brucei lacking the RNA-binding protein ZC3H30. PLoS Negl Trop Dis 12, e0006835
  Chakraborty, C and Clayton, C
  (See online at https://doi.org/10.1371/journal.pntd.0006835)
• (2018) The suppressive cap-binding-complex factor 4EIP is required for normal differentiation. Nucleic Acids Res 46, 8993-9010
  Terrao M, Kamanyi Marucha K, Mugo E, Droll D, Minia I, Egler F, Braun J, Clayton C
  (See online at https://doi.org/10.1101/314997)