Phosphagen kinases (PK's) are a widespread family of enzymes that catalyze the reversible transfer of phosphate from ATP to guanidino compounds, such as creatine and arginine. This reversible reaction allows for efficient buffering of the cellular ATP:ADP ratio in diverse eukaryotic lifeforms. For this reason, PK’s are crucial for stress resistance, resting energy metabolism, and basic growth and development pathways. The most widely studied PK, creatine kinase (CK), is known to be regulated through phosphorylation by adenosine monophosphate-activated protein kinase (AMPK) in mammals. However, no other PK’s have been studied as potential substrates of AMPK, limiting our evolutionary understanding of the mode of regulation, and limiting our functional understanding of other PK’s. In this preliminary study, we used an in vitro thiophosphorylation assay, and identified an arginine kinase isoform from C. elegans, F44, as a probable AMPK phosphorylation target. We related these findings to a recent study that examined a different aspect of the functional relationship between the two proteins, and then explored models of C. elegans AMPK signaling consistent with these two studies. This preliminary study lays the groundwork for further exploration of PK regulation by AMPK phosphorylation, and raises substantial questions regarding evolutionary divergence in core eukaryotic energetic pathways.


Fraga, Dean


Biochemistry and Molecular Biology


Biochemical Phenomena, Metabolism, and Nutrition


biochemistry, metabolism, enzymology, AMPK, phosphagen kinases

Publication Date


Degree Granted

Bachelor of Arts

Document Type

Senior Independent Study Thesis



© Copyright 2016 Andrew H. Greene