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001-es BibID:	BIBFORM016824
Első szerző:	Czikora István (vegyész, biokémikus)
Cím:	Characterization of the effect of TIMAP phosphorylation on its interaction with protein phosphatase 1 / Czikora István, Kim Kyung-mi, Kása Anita, Bécsi Bálint, Verin Alexander D., Gergely Pál, Erdődi Ferenc, Csortos Csilla
Dátum:	2011
ISSN:	0300-9084
Megjegyzések:	TIMAP, TGF-beta inhibited, membrane-associated protein, is highly abundant in endothelial cells (EC). We have shown earlier the involvement of TIMAP in PKA-mediated ERM (ezrin-radixin-moesin) dephosphorylation as part of EC barrier protection by TIMAP (Csortos et al., 2008). Emerging data demonstrate the regulatory role of TIMAP on protein phosphatase 1 (PP1) activity. We provide here evidence for specific interaction (Ka = 1.80 x 106 M-1) between non-phosphorylated TIMAP and the catalytic subunit of PP1 (PP1c) by surface plasmon resonance based binding studies. Thiophosphorylation of TIMAP by PKA, or sequential thiophosphorylation by PKA and GSK3β slightly modifies the association constant for the interaction of TIMAP with PP1c and decreases the rate of dissociation. However, dephosphorylation of phospho-moesin substrate by PP1cbeta is inhibited to different extent in the presence of non- (not, vert, similar60% inhibition), mono- (not, vert, similar50% inhibition) or double-thiophosphorylated (<10% inhibition) form of TIMAP. Our data suggest that double-thiophosphorylation of TIMAP has minor effect on its binding ability to PP1c, but considerably attenuates its inhibitory effect on the activity of PP1c. PKA activation by forskolin treatment of EC prevented thrombin evoked barrier dysfunction and ERM phosphorylation at the cell membrane (Csortos et al., 2008). With the employment of specific GSK3beta inhibitor it is shown here that PKA activation is followed by GSK3beta activation in bovine pulmonary EC and both of these activations are required for the rescuing effect of forskolin in thrombin treated EC. Our results suggest that the forskolin induced PKA/GSK3beta activation protects the EC barrier via TIMAP-mediated decreasing of the ERM phosphorylation level.
Tárgyszavak:	Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban TIMAP Protein Phosphatase 1 Moesin Surface Plasmon Resonance Molekuláris Medicina
Megjelenés:	Biochimie. - 93 : 7 (2011), p. 1139-1145. -
További szerzők:	Kim, Kyung-mi Kovács-Kása Anita (1983-) Bécsi Bálint (1981-) (vegyészmérnök) Verin, Alexander Gergely Pál (1947-) (biokémikus) Erdődi Ferenc (1953-) (biokémikus) Csortos Csilla (1956-) (biokémikus)
Pályázati támogatás:	TÁMOP-4.2.1/B-09/1/KONV-2010-0007 TÁMOP I. Protein foszfatázok szerepe az in vitro porcdifferenciációban és a mechano-transzdukcióban, II. Hypoglykaemiás szerek tervezése a glikogén foszforilázra (foszforilációval és defoszforilációval szabályozott kulcsenzim) ható molekulákkal TÁMOP-4.2.1/B-09/1/KONV-2010-0007 TÁMOP Biomolekuláris interakciók jellemzőinek kvantitatív meghatározása
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001-es BibID:	BIBFORM029024
Első szerző:	Kim, Kyung-mi
Cím:	Molecular characterization of myosin phosphatase in endothelium / Kyung-mi Kim, Csilla Csortos, Istvan Czikora, David Fulton, Nagavedi S. Umapathy, Gabor Olah, Alexander D. Verin
Dátum:	2012
ISSN:	0021-9541
Megjegyzések:	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 (CS1β) 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 CS1β 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 CS1β suggesting the importance of PPase 1 activity for the formation of functional complex of MYPT1/CS1β. 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. J. Cell. Physiol. 227: 1701-1708, 2012. © 2011 Wiley Periodicals, Inc.
Tárgyszavak:	Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban egyetemen (Magyarországon) készült közlemény
Megjelenés:	Journal of Cellular Physiology. - 227 : 4 (2012), p. 1701-1708. -
További szerzők:	Fulton, David Umapathy, Nagavedi S. Oláh Gábor Verin, Alexander Csortos Csilla (1956-) (biokémikus) Czikora István (1979-) (vegyész, biokémikus)
Internet cím:	Szerző által megadott URL DOI Intézményi repozitóriumban (DEA) tárolt változat
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