The group of Anne Schlaitz investigates the dynamic behavior of membrane-bound organelles during mitosis.
 
We are offering two Ph.D. student positions for the project:
 
"Structure, dynamics and functions of membrane-bound organelles during mitosis"
 
Payment will be according to the German TVL pay scale (TVL13, 65%). Start date should be between May and October, 2022.
 
Project Description
Background Mitosis is fundamental for all life and decades of research have elucidated how chromosomes and microtubules are remodeled to faithfully segregate chromosomes. In addition to the genetic information, daughter cells also need a full complement of membrane-bound organelles for their viability. And intriguingly, spindle assembly and chromosome segregation depend on organelles and organelle-associated proteins. Thus, membrane-bound organelles need to be restructured and repositioned in highly specific ways to ensure successful cell division but the mechanisms of mitotic organelle remodeling have largely remained elusive. We have recently characterized the membrane shaping and microtubule-binding proteins REEP3 and REEP4 as major organizers of endoplasmic reticulum (ER), which position and tubulate ER during mitosis. REEP4 additionally promotes the assembly of new nuclear pore complexes (NPCs) in the forming nuclear envelope. REEP3/REEP4 thereby promote correct nuclear envelope formation, chromosome segregation and cytokinesis, confirming the idea that correct organelle architecture is essential for cell division.
Thesis project This project will build on our recent findings and aims to elucidate mechanisms of cell cycle regulation and of microtubule-association of REEP3 and REEP4. To this end, we will investigate cell cycle-dependent differences in post-translational modifications and the interactomes of REEP3 and REEP4 and correlate these findings with the dynamic behavior and morphology of the ER. We will further investigate why ER is remodeled in such specific ways and how the organelle itself promotes successful mitosis.
Our biological model are human cultured cells and we employ a variety of cell culture techniques including CRISPR/Cas-mediated genome engineering. To analyze gene functions, we use a broad range of molecular cell biology methods, in particular quantitative high-resolution and super-resolution microscopy techniques. To identify cell cycle-specific interactors and modifications of REEP3 and REEP4 we will perform co-immunoprecipitations and proximity-dependent biotin-identification (BioID) experiments.
 
Further reading
Golchoubian B, Brunner A, Bragulat-Teixidor H, Neuner A, Akarlar BA, Ozlu N, Schlaitz AL (2022) Reticulon-like REEP4 at the inner nuclear membrane promotes nuclear pore complex formation. J Cell Biol 221:e202101049. Epub 2021 Dec 7.
Schlaitz AL (2020) The endoplasmatic reticulum during mitosis. Biospektrum 26:739-742. (in German)
Kumar D, Golchoubian B, Belevich I, Jokitalo E, Schlaitz AL (2019) REEP3 and REEP4 determine the tubular morphology of the endoplasmic reticulum during mitosis. Mol Biol Cell 30:1377-1389.
Schlaitz AL, Thompson J, Wong CC, Yates JR, 3rd, Heald R (2013) REEP3/4 ensure endoplasmic reticulum clearance from metaphase chromatin and proper nuclear envelope architecture. Dev Cell 26:315-323.
 
Personal qualifications
We look for students who are keen to investigate fundamental cell biological questions related to the morphogenesis and organization of membrane-bound organelles. Candidates should have a background in molecular cell biology, biochemistry or related fields, be passionate about experimental research, enjoy working in an international team and be comfortable communicating in English.
 
Application
Please send your application including a CV and contact information of two referees to anne.schlaitz@bzh.uni-heidelberg.de
 
Please find further information on our website at bzh.uni-heidelberg.de and do not hesitate to contact Anne Schlaitz directly with any questions: anne.schlaitz@bzh.uni-heidelberg.de