PMID- 23029056
OWN - NLM
STAT- MEDLINE
DCOM- 20130306
LR  - 20211021
IS  - 1932-6203 (Electronic)
IS  - 1932-6203 (Linking)
VI  - 7
IP  - 9
DP  - 2012
TI  - Characterization of PTPRG in knockdown and phosphatase-inactive mutant mice and 
      substrate trapping analysis of PTPRG in mammalian cells.
PG  - e45500
LID - 10.1371/journal.pone.0045500 [doi]
LID - e45500
AB  - Receptor tyrosine phosphatase gamma (PTPRG, or RPTPgamma) is a mammalian 
      receptor-like tyrosine phosphatase which is highly expressed in the nervous 
      system as well as other tissues. Its function and biochemical characteristics 
      remain largely unknown. We created a knockdown (KD) line of this gene in mouse by 
      retroviral insertion that led to 98-99% reduction of RPTPgamma gene expression. The 
      knockdown mice displayed antidepressive-like behaviors in the tail-suspension 
      test, confirming observations by Lamprianou et al. 2006. We investigated this 
      phenotype in detail using multiple behavioral assays. To see if the 
      antidepressive-like phenotype was due to the loss of phosphatase activity, we 
      made a knock-in (KI) mouse in which a mutant, RPTPgamma C1060S, replaced the wild 
      type. We showed that human wild type RPTPgamma protein, expressed and purified, 
      demonstrated tyrosine phosphatase activity, and that the RPTPgamma C1060S mutant was 
      completely inactive. Phenotypic analysis showed that the KI mice also displayed 
      some antidepressive-like phenotype. These results lead to a hypothesis that an 
      RPTPgamma inhibitor could be a potential treatment for human depressive disorders. In 
      an effort to identify a natural substrate of RPTPgamma for use in an assay for 
      identifying inhibitors, "substrate trapping" mutants (C1060S, or D1028A) were 
      studied in binding assays. Expressed in HEK293 cells, these mutant RPTPgammas 
      retained a phosphorylated tyrosine residue, whereas similarly expressed wild type 
      RPTPgamma did not. This suggested that wild type RPTPgamma might auto-dephosphorylate 
      which was confirmed by an in vitro dephosphorylation experiment. Using truncation 
      and mutagenesis studies, we mapped the auto-dephosphorylation to the Y1307 
      residue in the D2 domain. This novel discovery provides a potential natural 
      substrate peptide for drug screening assays, and also reveals a potential 
      functional regulatory site for RPTPgamma. Additional investigation of RPTPgamma activity 
      and regulation may lead to a better understanding of the biochemical 
      underpinnings of human depression.
FAU - Zhang, Wandong
AU  - Zhang W
AD  - Neuroscience Research, Lexicon Pharmaceuticals, Inc., The Woodlands, TX, USA. 
      zhangw96@gmail.com
FAU - Savelieva, Katerina V
AU  - Savelieva KV
FAU - Tran, David T
AU  - Tran DT
FAU - Pogorelov, Vladimir M
AU  - Pogorelov VM
FAU - Cullinan, Emily B
AU  - Cullinan EB
FAU - Baker, Kevin B
AU  - Baker KB
FAU - Platt, Kenneth A
AU  - Platt KA
FAU - Hu, Sean
AU  - Hu S
FAU - Rajan, Indrani
AU  - Rajan I
FAU - Xu, Nianhua
AU  - Xu N
FAU - Lanthorn, Thomas H
AU  - Lanthorn TH
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20120920
PL  - United States
TA  - PLoS One
JT  - PloS one
JID - 101285081
RN  - EC 3.1.3.48 (Receptor-Like Protein Tyrosine Phosphatases, Class 5)
SB  - IM
MH  - Animals
MH  - Female
MH  - Gene Knockout Techniques
MH  - Gene Order
MH  - Gene Targeting
MH  - HEK293 Cells
MH  - Humans
MH  - Male
MH  - Mice
MH  - Mice, Knockout
MH  - Motor Activity
MH  - Mutation
MH  - Phenotype
MH  - Phosphorylation
MH  - Physical Exertion
MH  - Receptor-Like Protein Tyrosine Phosphatases, Class 5/*genetics/*metabolism
MH  - Substrate Specificity
PMC - PMC3447766
COIS- Competing Interests: The authors have been employees of Lexicon Pharmaceuticals, 
      Inc., and from which authors have received salary payment and stock options. This 
      does not alter the authors' adherence to all the PLOS ONE policies on sharing 
      data and materials.
EDAT- 2012/10/03 06:00
MHDA- 2013/03/07 06:00
PMCR- 2012/09/20
CRDT- 2012/10/03 06:00
PHST- 2012/06/14 00:00 [received]
PHST- 2012/08/17 00:00 [accepted]
PHST- 2012/10/03 06:00 [entrez]
PHST- 2012/10/03 06:00 [pubmed]
PHST- 2013/03/07 06:00 [medline]
PHST- 2012/09/20 00:00 [pmc-release]
AID - PONE-D-12-17291 [pii]
AID - 10.1371/journal.pone.0045500 [doi]
PST - ppublish
SO  - PLoS One. 2012;7(9):e45500. doi: 10.1371/journal.pone.0045500. Epub 2012 Sep 20.