HD-PTP is a catalytically inactive tyrosine phosphatase due to a conserved divergence in its phosphatase domain.

ABSTRACT:

Background

The HD-PTP protein has been described as a tumor suppressor candidate and based on its amino acid sequence, categorized as a classical non-transmembrane protein tyrosine phosphatase (PTP). To date, no HD-PTP phosphorylated substrate has been identified and controversial results concerning its catalytic activity have been recently reported.

Methodology and results

Here we report a rigorous enzymatic analysis demonstrating that the HD-PTP protein does not harbor tyrosine phosphatase or lipid phosphatase activity using the highly sensitive DiFMUP substrate and a panel of different phosphatidylinositol phosphates. We found that HD-PTP tyrosine phosphatase inactivity is caused by an evolutionary conserved amino acid divergence of a key residue located in the HD-PTP pho

SUBMITTER: Gingras MC 

PROVIDER: S-EPMC2661844 | biostudies-literature | 2009

REPOSITORIES: biostudies-literature