Characterization of drug interaction of pore-exposed tyrosine residues

2013 ◽  
Vol 1 (Suppl. 1) ◽  
pp. A3.15
Author(s):  
Yaprak Dönmez Çakıl
Keyword(s):  
Drug Interaction ◽  
Tyrosine Residues

Identification and characterization of a new mammalian mitogen-activated protein kinase kinase, MKK2

1993 ◽  
Vol 13 (8) ◽  
pp. 4539-4548
Author(s):  
J Wu ◽  
J K Harrison ◽  
P Dent ◽  
K R Lynch ◽  
M J Weber ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Map Kinase ◽  
Protein Kinases ◽  
Map Kinases ◽  
Sodium Dodecyl ◽  
Rat Tissues ◽  
Tyrosine Residues ◽  
Mitogen Activated Protein ◽  
Map Kinase Kinase

Mitogen-activated protein (MAP) kinases are serine/threonine protein kinases activated by dual phosphorylation on threonine and tyrosine residues. A MAP kinase kinase (MKK1 or MEK1) has been identified as a dual-specificity protein kinase that is sufficient to phosphorylate MAP kinases p42mapk and p44mapk on the regulatory threonine and tyrosine residues. Because of the multiplicity of MAP kinase isoforms and the diverse circumstances and agonists leading to their activation, we thought it unlikely that a single MKK could accommodate this complexity. Indeed, two protein bands with MKK activity have previously been identified after renaturation following sodium dodecyl sulfate-polyacrylamide gel electrophoresis. We now report the molecular cloning and characterization of a second rat MAP kinase kinase cDNA, MKK2. MKK2 cDNA contains an open reading frame encoding a protein of 400 amino acids, 7 residues longer than MKK1 (MEK1). The amino acid sequence of MKK2 is 81% identical to that of MKK1, but nucleotide sequence differences occur throughout the aligned MKK2 and MKK1 cDNAs, indicating that MKK2 is the product of a distinct gene. MKK1 and MKK2 mRNAs are expressed differently in rat tissues. Both cDNAs when expressed in COS cells displayed the ability to phosphorylate and activate p42mapk and p44mapk, both MKK1 and MKK2 were activated in vivo in response to serum, and both could be phosphorylated and activated by the v-Raf protein in vitro. However, differences between MKK1 and MKK2 in sites of phosphorylation by proline-directed protein kinases predict differences in feedback regulation.

Characterization of proliferating human hepatocytes as a model system for drug interaction studies and toxicity screenings

2016 ◽  
Vol 258 ◽  
pp. S200
Author(s):  
A. Noerenberg ◽  
L. Tolosa ◽  
M. Gómez Lechón ◽  
N. Runge ◽  
T. Johannssen ◽  
...  
Keyword(s):  
Drug Interaction ◽  
Model System ◽  
Human Hepatocytes ◽  
Interaction Studies

scholarly journals Analysis of EYA3 Phosphorylation by Src Kinase Identifies Residues Involved in Cell Proliferation

2019 ◽  
Vol 20 (24) ◽  
pp. 6307 ◽  
Author(s):  
Aura E. Ionescu ◽  
Mihaela Mentel ◽  
Cristian V.A. Munteanu ◽  
Livia E. Sima ◽  
Eliza C. Martin ◽  
...  
Keyword(s):  
Kinase Activity ◽  
Src Kinase ◽  
Protein Tyrosine Phosphatases ◽  
Phosphorylation Sites ◽  
Src Tyrosine Kinase ◽  
Eyes Absent ◽  
Tyrosine Residues ◽  
Proliferative Effect ◽  
Phosphorylation Pattern

Eyes absent (EYA) are non-thiol-based protein tyrosine phosphatases (PTPs) that also have transcriptional co-activator functions. Their PTP activity is involved in various pathologies. Recently, we demonstrated that Src tyrosine kinase phosphorylates human EYA3 by controlling its subcellular localization. We also found EYA3′s ability to autodephosphorylate, while raising the question if the two opposing processes could be involved in maintaining a physiologically adequate level of phosphorylation. Using native and bottom-up mass spectrometry, we performed detailed mapping and characterization of human EYA3 Src-phosphorylation sites. Thirteen tyrosine residues with different phosphorylation and autodephosphorylation kinetics were detected. Among these, Y77, 96, 237, and 508 displayed an increased resistance to autodephosphorylation. Y77 and Y96 were found to have the highest impact on the overall EYA3 phosphorylation. Using cell cycle analysis, we showed that Y77, Y96, and Y237 are involved in HEK293T proliferation. Mutation of the three tyrosine residues abolished the pro-proliferative effect of EYA3 overexpression. We have also identified a Src-induced phosphorylation pattern of EYA3 in these cells. These findings suggest that EYA3′s tyrosine phosphorylation sites are non-equivalent with their phosphorylation levels being under the control of Src-kinase activity and of EYA3′s autodephosphorylation.

Molecular characterization of chicken Janus kinase2 (JAK2) and its expression analysis in different tissues and cell lines

2019 ◽  
Author(s):  
Abdalla A. Sayed
Keyword(s):  
Cell Lines ◽  
Expression Analysis ◽  
Time Course ◽  
Signal Transducer ◽  
Stat Proteins ◽  
Tyrosine Residues ◽  
Wide Range ◽  
Human And Mouse

Janus kinase2 (JAK2) is one of an important family that function primarily in signal transduction through contact with signal transducer and activator of transcription (STAT) proteins which reflects the high important role of JAK2 and its family. Chicken JAK2 protein is found to be formed of 1129 amino acids. The phosphorylation tyrosine residues were conserved between chicken, human and mouse. Expression analysis of chicken JAK2 showed a wide range of expression in all used tissues and cell lines. The expression was high in T-cell fraction when compared with that of B-cell one. The expression of chicken JAK2 showed a time course dependent of lipopolysaccharide (LPS) stimulation in spleen and bursa tissues and in IN24 cell line. The stimulation by LPS showed a high expression of chicken JAK2 in spleen and bursa by in-stiu hybridization studies.

scholarly journals Identification and characterization of a new mammalian mitogen-activated protein kinase kinase, MKK2.

1993 ◽  
Vol 13 (8) ◽  
pp. 4539-4548 ◽  
Author(s):  
J Wu ◽  
J K Harrison ◽  
P Dent ◽  
K R Lynch ◽  
M J Weber ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Map Kinase ◽  
Protein Kinases ◽  
Map Kinases ◽  
Sodium Dodecyl ◽  
Rat Tissues ◽  
Tyrosine Residues ◽  
Mitogen Activated Protein ◽  
Map Kinase Kinase

Mitogen-activated protein (MAP) kinases are serine/threonine protein kinases activated by dual phosphorylation on threonine and tyrosine residues. A MAP kinase kinase (MKK1 or MEK1) has been identified as a dual-specificity protein kinase that is sufficient to phosphorylate MAP kinases p42mapk and p44mapk on the regulatory threonine and tyrosine residues. Because of the multiplicity of MAP kinase isoforms and the diverse circumstances and agonists leading to their activation, we thought it unlikely that a single MKK could accommodate this complexity. Indeed, two protein bands with MKK activity have previously been identified after renaturation following sodium dodecyl sulfate-polyacrylamide gel electrophoresis. We now report the molecular cloning and characterization of a second rat MAP kinase kinase cDNA, MKK2. MKK2 cDNA contains an open reading frame encoding a protein of 400 amino acids, 7 residues longer than MKK1 (MEK1). The amino acid sequence of MKK2 is 81% identical to that of MKK1, but nucleotide sequence differences occur throughout the aligned MKK2 and MKK1 cDNAs, indicating that MKK2 is the product of a distinct gene. MKK1 and MKK2 mRNAs are expressed differently in rat tissues. Both cDNAs when expressed in COS cells displayed the ability to phosphorylate and activate p42mapk and p44mapk, both MKK1 and MKK2 were activated in vivo in response to serum, and both could be phosphorylated and activated by the v-Raf protein in vitro. However, differences between MKK1 and MKK2 in sites of phosphorylation by proline-directed protein kinases predict differences in feedback regulation.

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