Christian Kaiser

Christian Kaiser

Associate Professor

Dr. rer. nat. (PhD), Ludwig-Maximilians-Universität, Munich; Germany Max Planck Institute of Biochemistry, Martinsried, Germany

kaiser@jhu.edu
205 Biology East
410-516-4486
Group/Lab Website

Christian Kaiser joined the Department of Biology in 2013 as an Assistant Professor. He was promoted to Associate Professor (with tenure) in 2021. He holds a joint appointment in the Department of Biophysics. Prior to coming to Hopkins, he carried out doctoral work at the Max Planck Institute of Biochemistry and Ludwig Maximilian University in Germany, and postdoctoral work at the University of Texas Medical Branch at Galveston, and the University of California, Berkeley.

Our lab is interested in learning how cells make and maintain functional proteins. Protein biogenesis involves a variety of processes: Translation of the genetic code by the ribosome, targeting of the translation product to the proper cellular location, and folding into its native structure, often aided by molecular chaperones. We want to understand—at a mechanistic level—the molecular machines that synthesize, transport, and fold proteins. Knowing the molecular mechanisms will help us understand how these processes are tuned and synchronized.

We use optical tweezers to watch and manipulate the molecular machines involved in protein biogenesis. This single molecule approach helps us to overcome some of the challenges associated with studying these machines and the processes they carry out. Using reconstituted components, we are studying how the ribosome and the nascent chain interact with each other, how molecular chaperones affect protein folding and structural maintenance, and how the translocon helps polypeptides cross membranes and become functional. Ultimately, this will enable us to understand how cells obtain and maintain a functional proteome.

Selected recent publications

Maciuba K., Zhang F. & Kaiser C. M.(2021) Facile tethering of stable and unstable proteins for optical tweezers experiments. Biophysical Journal, 120(13):2691-2700

Maciuba K., Rajasekaran N., Chen X., Kaiser C. M. (2021) Co-translational folding of nascent polypeptides: Multi-layered mechanisms for the efficient biogenesis of functional proteins. Bioessays, 43(7):e2100042

Chen X., Rajasekaran N., Liu K. & Kaiser C. M. (2020) Synthesis runs counter to directional folding of a nascent protein domain. Nature Communications, 11(1):5096.

Gupta R., Toptygin D. & Kaiser C.M. (2020) The SecA motor generates mechanical force during protein translocation. Nature Communications, 11(1):3802

Liu, K., Chen, X., & Kaiser, C. M. (2019). Energetic dependencies dictate folding mechanism in a complex protein. PNAS, 116(51), 25641–25648. 

Liu, K., Maciuba, K., & Kaiser, C. M. (2019). The Ribosome Cooperates with a Chaperone to Guide Multi-domain Protein Folding. Molecular Cell, 74(2), 310-319.e7. 

Graduate Students

Riti Gupta

Kevin Maciuba

Xiuqi Chen

Nandakumar Rajasekaran

Hannah Haller

Postdoc

Nagaraju Chada

Undergraduate students

Annie Kim

Sunny Patel

Noah Sobel

Maggie Zhu