Mutational analysis of fructose-1,6-bis-phosphatase FBP1 indicates partially independent functions in gluconeogenesis and sensitivity to genotoxic stress
Authors:Ali Ghanem, Ana Kitanovic, Jinda Holzwarth, Stefan Wölfl
doi: 10.15698/mic2017.02.557
Volume 4, pp. 52 to 63, published 01/02/2017.
Institute of Pharmacy and Molecular Biotechnology, Heidelberg University, Heidelberg, Germany.
Keywords:
FBP1, S. cerevisiae, MMS, genotoxicity, DNA-damage, gluconeogenesis.
Corresponding Author(s):
Conflict of interest statement:
The authors declare no conflict of interest.
Please cite this article as:
Ali Ghanem, Ana Kitanovic, Jinda Holzwarth, Stefan Wölfl (2017). Mutational analysis of fructose-1,6-bis-phosphatase FBP1 indicates partially independent functions in gluconeogenesis and sensitivity to genotoxic stress. Microbial Cell 4(2): 52-63.
© 2017 Ghanem et al. This is an open-access article released under the terms of the Creative Commons Attribution (CC BY) license, which allows the unrestricted use, distribution, and reproduction in any medium, provided the original author and source are acknowledged.
Abstract:
Fructose-1,6-bisphosphatase (FBP1) is a key enzyme in the evolutionary conserved pathway of gluconeogenesis. We had shown in an earlier study that FBP1 is involved in the response and sensitivity to methyl-methanesulfonate (MMS)-induced DNA damage in yeast. In the work presented here we performed an alanine screen mutational analysis of several evolutionary conserved amino acid residues of FBP1, which were selected based on conserved residues and structural studies of mammalian and yeast homologues of FBP1. Mutants were examined for enzymatic activity, and yeast cells expressing these mutants were tested for growth on non-fermentable and MMS-containing media. The results obtained support predicted vital roles of several residues for enzymatic activity and led to the identification of residues indispensable for the MMS-sensitizing effect. Despite an overlap between these two properties, careful analysis revealed two mutations, Asn75 and His324, which decouple the enzymatic activity and the MMS-sensitizing effect, indicating two distinctive biological activities linked in this key gluconeogenesis enzyme.