Date of Award


Publication Type

Master Thesis

Degree Name



Chemistry and Biochemistry

First Advisor

Vacratsis, Panayiotis (Chemistry and Biochemistry)





Creative Commons License

Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.


MTMR2 is an active member of the MTM family of inositol lipid phosphatases and the physiological substrates for MTMR2 play key roles in endosomal trafficking. Additionally, loss of function mutations in MTMR2, have been associated with the peripheral neuromuscular disorder CMT4B1. In these studies we used mass spectrometry (MS) based methods to identify a novel high stoichiometry phosphorylation site at Ser58 on MTMR2. Further analysis has illustrated that a phosphorylation deficient MTMR2 (S58A) displayed constitutive localization to early endocytic structures. Moreover, we determined that the subcellular targeting of S58A was accompanied by depletion of PI(3)P and an increase in the phosphorylation of ERK1/2. Recently we have used in vitro kinase assays to determine that ERK1/2 phosphorylates Ser58. Furthermore, we have recently confirmed a C-terminal phosphorylation site at Ser631 and generated combinatorial mutants which have shown to display characteristic localization to a distinct subset of endocytic compartments as well as sustained ERK1/2 activation.