Dual-Specificity Phosphoprotein Phosphatase

2020 ◽  
Author(s):  
Keyword(s):  
Phosphoprotein Phosphatase ◽  
Dual Specificity

Effect of Thrombin on Phosphorylation of Platelet Membrane Proteins

1976 ◽  
Vol 35 (03) ◽  
pp. 635-642 ◽  
Author(s):  
M Steiner
Keyword(s):  
Protein Kinase ◽  
Kinase Activity ◽  
Qualitative Change ◽  
Protein Kinase Activity ◽  
Protein Substrates ◽  
Phosphoprotein Phosphatase ◽  
Progressive Loss ◽  
Platelet Membranes ◽  
Endogenous Protein ◽  
Considerable Loss

SummaryThe effect of thrombin on the phosphorylating activity of platelet membranes was compared to that of trypsin. Preincubation of non-32P phosphorylated platelet membranes with or without either of these two enzymes resulted in a considerable loss of membrane protein kinase activity which was most severe when trypsin was used. Protein kinase activity and endogenous protein acceptors decreased in parallel. 32P-phosphorylated membranes showed a slow but progressive loss of label which was accelerated by trypsin. Thrombin under these conditions prevented the loss of 32P-phosphate. These results are interpreted to indicate a thrombin-induced destruction of a phosphoprotein phosphatase. The protein kinase activity of phosphorylated platelet membranes using endogenous or exogenous protein substrates showed a significant reduction compared to non-phosphorylated membranes suggesting a deactivation of protein kinase by phosphorylation of platelet membranes. Neither thrombin nor trypsin caused a qualitative change in the membrane polypeptides accepting 32P-phosphate but resulted in quantitative alterations of their ability to become phosphorylated.

Avances moleculares en el síndrome de Down y su posible aplicación en neurología

2015 ◽  
Vol 20 (1) ◽  
pp. 65-78
Author(s):  
Manuel Ramos-Kuri ◽  
Enrique Salgado-Sánchez
Keyword(s):  
Tyrosine Phosphorylation ◽  
Dual Specificity

Se revisan los avances recientes en el síndrome de Down (SD), haciendo énfasis en su terapia molecular y potencial terapéutico en enfermedades como Alzheimer (EA) y otros trastornos de déficit cognoscitivo. El SD es la principal causa de retraso mental a nivel mundial, causado por la trisomía completa o parcial del cromosoma 21, y es bien conocida su estrecha relación con la EA, de inicio muy temprano. La sobre-expresión de genes del cromosoma 21 es la principal causa del SD, pero se han identificado algunos genes especialmente importantes. Por ejemplo, el gen DYRK1A (dual specificity tyrosine phosphorylation-regulated kinase) participa en el déficit cognitivo tanto en SD como en la EA. Su fisiopatología es porque el exceso de DYRK1A hiper fosforila a la proteína precursora de amiliode (APP) y a la unidad asociada a tubulina (TAU) proteínas bien conocidas en la génesis de la EA. Otra aplicación potencial es que los pacientes con SD presentan menor incidencia de tumores sólidos; su mecanismo es inhibiendo angiogénesis, por inhibición del factor de crecimiento vascular endotelial (VEGF) a través de la inhibición de calcineurina, gracias a la sobre-expresión del gen DSCR-1 presente en el cromosoma 21. Aunque el SD aún no cuenta con terapia específica, se realiza terapia molecular en modelos murinos con SD, con dos péptidos intestinales vasoactivos NAP y SAL. Los ratones así tratados mostraron una clara disminución en el déficit cognoscitivo, sugiriendo un alto potencial terapéutico para el SD; así como, otros tipos de retardo mental y déficit de aprendizaje.

Study on interaction between Duodenase - Protease with Dual Specificity and Inhibitors of Bowman-Birk Family

2002 ◽  
Vol 9 (2) ◽  
pp. 139-144 ◽  
Author(s):  
Inna Gladysheva ◽  
Natalia Popykina ◽  
Tatyana Zamolodchikova ◽  
Natalia Larionova
Keyword(s):  
Dual Specificity

scholarly journals Characterization of Caenorhabditis elegans Homologs of the Down Syndrome Candidate Gene DYRK1A

Genetics ◽  
2003 ◽  
Vol 163 (2) ◽  
pp. 571-580 ◽  
Author(s):  
William B Raich ◽  
Celine Moorman ◽  
Clay O Lacefield ◽  
Jonah Lehrer ◽  
Dusan Bartsch ◽  
...  
Keyword(s):  
Down Syndrome ◽  
Caenorhabditis Elegans ◽  
Trisomy 21 ◽  
Gene Dosage ◽  
Inducible Promoters ◽  
C Elegans ◽  
Dual Specificity ◽  
Specificity Protein

Abstract The pathology of trisomy 21/Down syndrome includes cognitive and memory deficits. Increased expression of the dual-specificity protein kinase DYRK1A kinase (DYRK1A) appears to play a significant role in the neuropathology of Down syndrome. To shed light on the cellular role of DYRK1A and related genes we identified three DYRK/minibrain-like genes in the genome sequence of Caenorhabditis elegans, termed mbk-1, mbk-2, and hpk-1. We found these genes to be widely expressed and to localize to distinct subcellular compartments. We isolated deletion alleles in all three genes and show that loss of mbk-1, the gene most closely related to DYRK1A, causes no obvious defects, while another gene, mbk-2, is essential for viability. The overexpression of DYRK1A in Down syndrome led us to examine the effects of overexpression of its C. elegans ortholog mbk-1. We found that animals containing additional copies of the mbk-1 gene display behavioral defects in chemotaxis toward volatile chemoattractants and that the extent of these defects correlates with mbk-1 gene dosage. Using tissue-specific and inducible promoters, we show that additional copies of mbk-1 can impair olfaction cell-autonomously in mature, fully differentiated neurons and that this impairment is reversible. Our results suggest that increased gene dosage of human DYRK1A in trisomy 21 may disrupt the function of fully differentiated neurons and that this disruption is reversible.

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