PMID- 21678426
OWN - NLM
STAT- MEDLINE
DCOM- 20120305
LR  - 20211020
IS  - 1097-4652 (Electronic)
IS  - 0021-9541 (Print)
IS  - 0021-9541 (Linking)
VI  - 227
IP  - 4
DP  - 2012 Apr
TI  - Molecular characterization of myosin phosphatase in endothelium.
PG  - 1701-8
LID - 10.1002/jcp.22894 [doi]
AB  - The phosphorylation status of myosin light chain (MLC) is regulated by both MLC 
      kinases and type 1 Ser/Thr phosphatase (PPase 1), MLC phosphatase (MLCP) 
      activities. The activity of the catalytic subunit of MLCP (CS1beta) towards myosin 
      depends on its associated regulatory subunit, namely myosin PPase targeting 
      subunit 1 (MYPT1). Our previously published data strongly suggested the 
      involvement of MLCP in endothelial cell (EC) barrier regulation. In this study, 
      our new data demonstrate that inhibition of MLCP by either CS1beta or MYPT1 
      siRNA-based depletion results in significant attenuation of purine nucleotide 
      (ATP and adenosine)-induced EC barrier enhancement. Consistent with the data, 
      thrombin-induced EC F-actin stress fiber formation and permeability increase were 
      attenuated by the ectopic expression of constitutively active (C/A) MYPT1. The 
      data demonstrated for the first time direct involvement of MLCP in EC barrier 
      enhancement/protection. Cloning of MYPT1 in human pulmonary artery EC (HPAEC) 
      revealed the presence of two MYPT1 isoforms, long and variant 2 (V2) lacking 56 
      amino acids from 553 to 609 of human MYPT1 long, which were previously identified 
      in HeLa and HEK 293 cells. Our data demonstrated that in Cos-7 cells ectopically 
      expressed EC MYPT1 isoforms co-immunoprecipitated with intact CS1beta suggesting the 
      importance of PPase 1 activity for the formation of functional complex of 
      MYPT1/CS1beta. Interestingly, MYPT1 V2 shows decreased binding affinity compared to 
      MYPT1 long for radixin (novel MLCP substrate and a member of ERM family 
      proteins). These results suggest functional difference between EC MYPT1 isoforms 
      in the regulation of MLCP activity and cytoskeleton.
CI  - Copyright (c) 2011 Wiley Periodicals, Inc.
FAU - Kim, Kyung-Mi
AU  - Kim KM
AD  - Vascular Biology Center, Georgia Health Sciences University, Augusta, Georgia 
      30912, USA.
FAU - Csortos, Csilla
AU  - Csortos C
FAU - Czikora, Istvan
AU  - Czikora I
FAU - Fulton, David
AU  - Fulton D
FAU - Umapathy, Nagavedi S
AU  - Umapathy NS
FAU - Olah, Gabor
AU  - Olah G
FAU - Verin, Alexander D
AU  - Verin AD
LA  - eng
GR  - HL083327/HL/NHLBI NIH HHS/United States
GR  - R01 HL083327/HL/NHLBI NIH HHS/United States
GR  - R01 HL067307/HL/NHLBI NIH HHS/United States
GR  - R01 HL067307-08/HL/NHLBI NIH HHS/United States
GR  - R01 HL080675/HL/NHLBI NIH HHS/United States
GR  - HL 067307/HL/NHLBI NIH HHS/United States
GR  - R01 HL080675-04/HL/NHLBI NIH HHS/United States
GR  - R01 HL083327-05/HL/NHLBI NIH HHS/United States
PT  - Journal Article
PT  - Research Support, N.I.H., Extramural
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - J Cell Physiol
JT  - Journal of cellular physiology
JID - 0050222
RN  - 0 (Cytoskeletal Proteins)
RN  - 0 (DNA-Binding Proteins)
RN  - 0 (ETV5 protein, human)
RN  - 0 (Isoenzymes)
RN  - 0 (Membrane Proteins)
RN  - 0 (Protein Subunits)
RN  - 0 (RNA, Small Interfering)
RN  - 0 (Recombinant Proteins)
RN  - 0 (Transcription Factors)
RN  - 144517-21-5 (radixin)
RN  - EC 3.1.3.53 (Myosin-Light-Chain Phosphatase)
RN  - EC 3.1.3.53 (PPP1R12A protein, human)
SB  - IM
MH  - Animals
MH  - Base Sequence
MH  - COS Cells
MH  - Capillary Permeability
MH  - Cells, Cultured
MH  - Chlorocebus aethiops
MH  - Cloning, Molecular
MH  - Cytoskeletal Proteins/metabolism
MH  - DNA-Binding Proteins/metabolism
MH  - Endothelial Cells/*enzymology
MH  - Humans
MH  - Isoenzymes/chemistry/genetics/metabolism
MH  - Membrane Proteins/metabolism
MH  - Myosin-Light-Chain Phosphatase/chemistry/genetics/*metabolism
MH  - Protein Interaction Domains and Motifs
MH  - Protein Subunits
MH  - RNA, Small Interfering/genetics
MH  - Recombinant Proteins/chemistry/genetics/metabolism
MH  - Substrate Specificity
MH  - Transcription Factors/metabolism
PMC - PMC3695713
MID - NIHMS305975
EDAT- 2011/06/17 06:00
MHDA- 2012/03/06 06:00
PMCR- 2013/06/28
CRDT- 2011/06/17 06:00
PHST- 2011/06/17 06:00 [entrez]
PHST- 2011/06/17 06:00 [pubmed]
PHST- 2012/03/06 06:00 [medline]
PHST- 2013/06/28 00:00 [pmc-release]
AID - 10.1002/jcp.22894 [doi]
PST - ppublish
SO  - J Cell Physiol. 2012 Apr;227(4):1701-8. doi: 10.1002/jcp.22894.