Molecular Microbiology and Genetics

Mass Spectrometry - Yeast group

Service Unit LCMS Proteinanalytics

RACK1/Asc1 in signal transduction and ribosomal control in Saccharomyces cerevisiae

Cellular differentiation and physiological development depend on signaling circuits that finally trigger gene and protein expression according to spatial-temporal needs. The imprint of signals to whole functional entities such as ribosomes depends on scaffold proteins, e.g. RACK1/Asc1 at ribosomes. The gearing of anabolic processes for DNA, RNA and protein syntheses with the deactivation/degradation of their respective macromolecular machineries demands for proteins that distribute information selectively to the associated processes. The RACK1/Asc1 protein is a kinase substrate and itself affects the phosphorylation of many other proteins and with that finally the cellular proteome. We hypothesize that the RACK1/Asc1 scaffold mediates protein arrangements within the local microenvironment of the busy head region of the 40S ribosomal subunit and by that influences activity and fate of ribosomes. By the use of the in vivo labeling technique Biotin IDentification (BioID and Split-BioID) we currently investigate the molecular environments of RACK1/Asc1 within the cell according to growth states and genetic modifications. We recently monitored the presence of proteins at the 40S ribosomal head region that are indicative for active ribosomes (e.g. mRNA-binding proteins, translation initiation factors, and the cap-binding protein), for stalled ribosomes (the ribosome clamping factor Stm1), and for the degradation of proteins (the ribophagy factors Ubp3/Bre5). We intend to dissect the dynamic interactions at the 40S head region responsible for the decisions for distinct ribosomal states.




Group members:

Group leader:

Dr. Oliver Valerius

Scientific staff:

Dr. Kerstin Schmitt

Former member:

Dr. Nadine Opitz (née Smolinski)


Funding:

  • DFG project “Role of Asc1 role in MAP kinase and cAMP/PKA signaling“

  • Göttingen Graduate School for Neurosciences, Biophysics, and Molecular Biosciences (GGNB)