Chair of Cell and Developmental Biology (Zoology I)

kramer lab

The major aim of our research is to understand how spatial aspects of mRNA metabolism contribute to the posttranscriptional regulation of gene expression in eukaryotes.

Research synopsis

About half of eukaryotic gene expression regulation is estimated to occur posttranscriptional, with the regulation of mRNA metabolism playing a major role. Thereby, the localisation of an mRNA often determines its function and can be very dynamic. Various triggers for example cause most mRNAs to move from translating polysomes into stress granules, which are macroscopic aggregates of protein and RNA. Bulk mRNAs are believed to be stored in these granules to allow for the selected translation of stress response proteins and can return back to translation after stress release. Another example is the localisation of a specific mRNA to an intracellular sub-compartment, for example for localised translation. The mechanisms that determine and regulate intracellular mRNA localisation still remain poorly understood, in any organism.

As a model system, we are am using Trypanosoma brucei, a single cell flagellate that shuttles between the tsetse fly insect vector and its mammalian host and is responsible for human African trypanosomiasis. For the questions I am interested in, trypanosomes have several advantages: i) The parasites are true experts in posttranscriptional gene regulation, as they lack any transcriptional control of genes transcribed by RNA polymerase II ii) Trypanosomes frequently change the expression of a large fraction of their genome, during their complex life cycle or in response to stress; many of these changes can be simulated in vitro and are highly useful experimental tools. iii) Trypanosomes have highly asymmetrical cell architectures with well-positioned single organelles, which hugely facilitates the detection and description of positional changes of mRNA molecules or ribonucleoprotein granules (RNA granules).

Recent publications

Londono, P. A. C., Banholzer, N., Bannerman, B. P. & Kramer, S. (2021) Is mRNA decapping activity of ApaH like phosphatases (ALPH’s) the reason for the loss of cytoplasmic ALPH’s in all eukaryotes but Kinetoplastida? doi:10.21203/rs.3.rs-192222/v1. PMID: 34162332

Kramer, S., Meyer-Natus, E., Stigloher, C., Thoma, H., Schnaufer, A. and Engstler M. (2020) Parallel monitoring of RNA abundance, localisation and compactness with correlative single molecule FISH on LR White embedded samples. Nucleic Acids Res 49, gkaa1142- PMID: 33275141

Goos C, Dejung M, Wehman AM, Meyer-Natus E, Schmidt J, SunterJ , Engstler M, Butter F and Kramer S. (2019) Trypanosomes can initiate nuclear export co-transcriptionally. Nucleic Acid research, in press PMID:30418648

Kramer S and McLennan AG. (2018) The complex enzymology of mRNA decapping: enzymes of four classes cleave pyrophosphate bounds.WIREs RNA 38, e1511–17. PMID:30345629

Zoltner, M., Krienitz, N., Field, M. C. & Kramer, S (2018). Comparative proteomics of the two T. brucei PABPs suggests that PABP2 controls bulk mRNA. PLoS Necl Trop Dis 12, e0006679. PMID:30040867

Bannerman, B P, Kramer, S, Dorrell, R . & Carrington, M (2018) Multispecies reconstructions uncover widespread conservation, and lineage-specific elaborations in eukaryotic mRNA metabolism. PLoS ONE 13, e0192633–23. PMID:29561870

Kramer S (2017). The ApaH-like phosphatase TbALPH1 is the major mRNA decapping enzyme of trypanosomes. PLoS Pathog 13: e1006456 PMID:28628654

Zimmermann, H., Subota, I., Batram, C., Kramer, S., Janzen, C. J., Jones, N. G., & Engstler, M (2017). A quorum sensing-independent path to stumpy development in Trypanosoma brucei. PLoS Pathog., 13:e1006324–33. PMID:28394929

Kramer S (2017). Simultaneous detection of mRNA transcription and decay intermediates by dual colour single mRNA FISH on subcellular resolution. Nucleic Acids Res 45: e49 PMID:27940558

Goos C, Dejung M, Janzen CJ, Butter F and Kramer S (2017). The nuclear proteome of Trypanosoma brucei. PLoS One 12(7):e0181884. PMID:28727848

full list of publications


спасибо GORBI

30th August 2022

... the Kramer lab would not exist without you.


Nuclear export in Potsdam

Jul 2022

Johanna and Bernardo present their work at the DGZ meeting "Life at the edge: the nuclear envelope and nucleocytoplasmic transport".

Visitors from Prague

11th to 13th May, 2022

Our collaborators from Martin Zoltners lab in Prague visited. We had a great and productive time together, discussing our joined project and plans for the next grant application. 

Discussing ALPH in Warsaw

7th Dec 2021

Start up meeting in Warsaw with Maria GoRNA and Martin Zolter to plan how to employ ALPH as a drug target.

Joined Lab-Meeting in Prague

Sep 2021

We had our first in-person meeting since Corona: with our collaborators from the Zoltner lab at the Biocev near Prague. Zoom can never replace real meetings.

We have moved to our new lab!

2nd and 3rd June, 2021

This week we have moved into our new lab and we even found a place for the picture that we inherited. There are still some small issues to sort out, but in principle the lab is already fully functional and we look forwards to testing it with exciting experiments. 

14 DAYS of Quarantine

April/May 2021

Covid once again, Lisa got the virus, but nobody else got infected :-). Here are images from our (almost) daily quarantine Zoom Meetings.

First PhD defence of the Kramer lab

14th April 2021

The Kramer lab has its first Doktor! Carina Goos successfully defended her Thesis. Many congratulations, Carina!

RNA 2019

June, 2019

We met with our Polish Collaboraters from the laboratory of Maria Gorna at the RNA society meeting in Krakow. Together we will unravel the secrets of the trypanosome decapping enzyme !


mRNA granules

Many non-polysomal mRNAs aggregate into RNA granules, large ribonucleoprotein particles. What is the composition and function of RNA granules and how are they regulated?

mRNA decay

The first step in mRNA decay is the removal of the 5' cap. In trypanosomes, this is done by a highly unusual enzyme, an ApaH like phosphatase.

mRNA export

We recently found that trypanosomes can export their mRNAs co-transcriptionally.


Nico Ankenbrand

José Carlos Quilles Junior

Silke Braune

Amelie Eder

PhD, Postdoc

Claudia Moreira (2019)


Establishing novel proximity labelling techniques (Postdoc)


Carina Goos (2017 / Defense 2021)


Purification and characterisation of trypanosome nuclear periphery granules

Master Students

Johanna Odenwald (2021)

Interactions and Function of a novel mRNA decapping enzyme from Trypanosoma brucei

Andrea Reichert (2018)

Untersuchungen zur Funktion der spezifischen Lokalisation des T. brucei mRNA-Decapping-Enzyms

Nadja Sauer (2016) 

In vivo Markierung von mRNAs in RNP Granula durch photoaktivierbare, abstandsabhängige Biotinylierung: Etablierung der Methode

Hanna Thoma (2016)

Warum sind für ribosomale Proteine kodierende mRNAs aus Stress-Granula ausgeschlossen?

Christina Julia Lorenz (2015, extern in Cambridge)

Identification of interaction partners of the DEAD-box RNA helicase DHH1 in Trypanosoma brucei

Nina Krienitz (2015, extern Cambridge and Dundee)

Implementation of a novel cryomilling method to analyse protein and RNA interactions of the poly(A)-binding proteins in Trypanosoma brucei

Melanie Fritz (2014)

Zusammensetzung und Ultrastruktur von Stress-Granula in Trypanosoma brucei brucei

Bachelor Students

Marko Korb (2022)

Serum-Abhängigkeit von Trypanosoma brucei brucei Kulturen: Untersuchungen zur Reduktion der benötigten FCS-Konzentration

Lisa Marie-Hofacker (2021)

Etablierung einer induzierbaren Bio-ID Methode in Trypanosoma brucei

Nicole Banholzer (2019)

Charakterisierung eines neuen mRNA Decapping-Enzyms aus Trypanosomen

Anna Sophie Kreis (2019)

Etablierung einer Methode zur mRNA-Visualisierung mittels CRISPR/dCAS13

Laura Gauglitz (2018)

Etablierung einer neuen BioID Methode in Trypanosomen

Laura Peters (2017)

Warum sind mRNAs, die für ribosomale Proteine kodieren, aus Stress-Granula ausgeschlossen?

Till Elharrar (2015)

Validierung der Lokalisation zu ‘Nuclear periphery granules’ von neu identifizierten Proteinkandidaten

Nadja Sauer (2014)

Überprüfung neuer Stressgranula-Protein-Kandidaten in Trypanosoma brucei

Daja Schichler (2014)

Analyse von RNA-Granula in Trypanosoma brucei

Melanie Fritz (2012)

Charakterisierung von Stress-Granula in Trypanosoma brucei brucei

Mario Hofweber (2012)

Ist das trypanosomale P-body Protein SCD6 ein Multimer?


Delara Shahidi (2021)

Sisco Jung (2021)

Frederik Heim

Corinna Kronenthaler

Johannes Schmidt

Bilal Tetik

Susheela Behera