Arginine kinase of myxococcus xanthus influences development in a manner dependent on the conditions of development

Thomas Bohl, The College of Wooster

Abstract

Arginine kinase (AK) is a member of the phosphagen kinase family, which catalyze the reversible transfer of the γ-phosphate from adenosine triphosphate (ATP) to the guanidino group of another molecule. AK activity produces a pool of phosphoarginine that can be utilized in times of ATP depletion to regenerate ATP. This may affect metabolism not only by helping to buffer ATP concentrations but also by inhibiting the formation of adenosine monophosphate (AMP), a potent regulator of many metabolic pathways. AK converts ADP to ATP and thus inhibiting adenylate kinse, which uses two ADPs to form ATP and AMP. Myxococcus xanthus is a soil bacteria used as a model for multicellular behavior in bacteria because the cells aggregate to form mound-like fruiting bodies in which some of the cells transform into spores when starved. This developmental process has been found to be inhibited in AK knock-out mutants of M. xanthus, which is one of few bacteria known to encode a phosphagen kinase. However, osmotic stress by sucrose (0.2M) or NaCl (0.2M) was found to partially rescue development of the mutant strain on submerged MC7 plates. This study expanded the data of previous studies by examining the effects of osmotic stress on different developmental media (TPM and CF agar). In addition, plasmids were produced that can be used to insert the M. xanthus AK gene or other AK genes into the mutant strain's genome. This will help determine the function of M. xanthus AK by showing whether different AKs can restore the wild type phenotype.