TheMycobacterium tuberculosis serine/threonine kinase PknL phosphorylates Rv2175c: Mass spectrometric profiling of the activation loop phosphorylation sites and their role in the recruitment of Rv2175c

PROTEOMICS ◽  
2008 ◽  
Vol 8 (3) ◽  
pp. 521-533 ◽  
Author(s):  
Marc J. Canova ◽  
Romain Veyron-Churlet ◽  
Isabelle Zanella-Cleon ◽  
Martin Cohen-Gonsaud ◽  
Alain J. Cozzone ◽  
...  
Keyword(s):  
Mass Spectrometric ◽  
Activation Loop ◽  
Phosphorylation Sites ◽  
Serine Threonine Kinase ◽  
Threonine Kinase

scholarly journals Crystal structure of microtubule affinity-regulating kinase 4 catalytic domain in complex with a pyrazolopyrimidine inhibitor

2016 ◽  
Vol 72 (2) ◽  
pp. 129-134 ◽  
Author(s):  
John S. Sack ◽  
Mian Gao ◽  
Susan E. Kiefer ◽  
Joseph E. Myers ◽  
John A. Newitt ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Catalytic Domain ◽  
Neurofibrillary Tangle ◽  
Binding Pocket ◽  
Atp Binding ◽  
Activation Loop ◽  
Serine Threonine Kinase ◽  
Atp Binding Site ◽  
Threonine Kinase ◽  
Catalytic Loop

Microtubule-associated protein/microtubule affinity-regulating kinase 4 (MARK4) is a serine/threonine kinase involved in the phosphorylation of MAP proteins that regulate microtubule dynamics. Abnormal activity of MARK4 has been proposed to contribute to neurofibrillary tangle formation in Alzheimer's disease. The crystal structure of the catalytic and ubiquitin-associated domains of MARK4 with a potent pyrazolopyrimidine inhibitor has been determined to 2.8 Å resolution with anRworkof 22.8%. The overall structure of MARK4 is similar to those of the other known MARK isoforms. The inhibitor is located in the ATP-binding site, with the pyrazolopyrimidine group interacting with the inter-lobe hinge region while the aminocyclohexane moiety interacts with the catalytic loop and the DFG motif, forcing the activation loop out of the ATP-binding pocket.

New insights into PKC family affairs: three novel phosphorylation sites in PKCϵ and at least one is regulated by PKCα

2008 ◽  
Vol 411 (2) ◽  
pp. e15-e16 ◽  
Author(s):  
Christer Larsson
Keyword(s):  
Phosphorylation Sites ◽  
Functional Importance ◽  
Serine Threonine Kinase ◽  
Threonine Kinase ◽  
Cellular Processes ◽  
Biochemical Journal ◽  
Pkc Isoforms ◽  
Evolutionarily Conserved ◽  
The Individual

PKCϵ (protein kinase Cϵ) is a serine/threonine kinase, and a member of the PKC family of isoforms. The different PKC isoforms regulate many cellular processes of importance for disease. It is therefore desirable to obtain tools to specifically modulate the activity of the individual isoforms and to develop markers of PKC activity. The paper by Durgan et al. in this issue of the Biochemical Journal has taken us some steps further towards these goals. In the paper they identify three previously unknown phosphorylation sites in PKCϵ. All of them are specific for the ϵ isoform, evolutionarily conserved and tightly regulated. The phosphorylation of one site is critical for the binding of PKCϵ to 14-3-3β, suggesting it is of functional importance. The results provide important novel findings that uncover new aspects of PKCϵ regulation and reveal new possibilities for detecting PKCϵ activity in situ.

scholarly journals The mechanism of activation of monomeric B-Raf V600E

2021 ◽  
Author(s):  
Ryan C Maloney ◽  
Mingzhen Zhang ◽  
HYUNBUM JANG ◽  
Ruth Nussinov
Keyword(s):  
Hydrophobic Interactions ◽  
Salt Bridge ◽  
Activation Loop ◽  
Wild Type ◽  
Serine Threonine Kinase ◽  
Threonine Kinase ◽  
Oncogenic Mutations ◽  
In The Wild ◽  
Activation Pathways ◽  
The Impact

Oncogenic mutations in the serine/threonine kinase B-Raf, particularly the V600E mutation, are frequent in cancer, making it a major drug target. Although much is known about B-Raf's active and inactive states, questions remain about the mechanism by which the protein changes between these two states. Here, we utilize molecular dynamics to investigate both wild-type and V600E B-Raf to gain mechanistic insights into the impact of the Val to Glu mutation. The results show that the wild-type and mutant follow similar activation pathways involving an extension of the activation loop and an inward motion of the αC-helix. The V600E mutation, however, destabilizes the inactive state by disrupting hydrophobic interactions present in the wild-type structure while the active state is stabilized through the formation of a salt bridge between Glu600 and Lys507. Additionally, when the activation loop is extended, the αC-helix is able to move between an inward and outward orientation as long as the DFG motif adopts a specific orientation. In that orientation Phe595 rotates away from the αC-helix, allowing the formation of a salt bridge between Lys483 and Glu501. These mechanistic insights have implications for the development of new Raf inhibitors.

scholarly journals The structures of the kinase domain and UBA domain of MPK38 suggest the activation mechanism for kinase activity

2014 ◽  
Vol 70 (2) ◽  
pp. 514-521 ◽  
Author(s):  
Yong-Soon Cho ◽  
Jiho Yoo ◽  
Soomin Park ◽  
Hyun-Soo Cho
Keyword(s):  
Drug Target ◽  
Leucine Zipper ◽  
Kinase Domain ◽  
Activation Mechanism ◽  
Activation Loop ◽  
Serine Threonine Kinase ◽  
Threonine Kinase ◽  
Extended Sequence ◽  
Uba Domain ◽  
Cleft Closure

Murine protein serine/threonine kinase 38 (MPK38) is the murine orthologue of human maternal embryonic leucine-zipper kinase (MELK), which belongs to the SNF1/AMPK family. MELK is considered to be a promising drug target for anticancer therapy because overexpression and hyperactivation of MELK is correlated with several human cancers. Activation of MPK38 requires the extended sequence (ExS) containing the ubiquitin-associated (UBA) linker and UBA domain and phosphorylation of the activation loop. However, the activation mechanism of MPK38 is unknown. This paper reports the crystal structure of MPK38 (T167E), which mimics a phosphorylated state of the activation loop, in complex with AMP-PNP. In the MPK38 structure, the UBA linker forces an inward movement of the αC helix. Phosphorylation of the activation loop then induces movement of the activation loop towards the C-lobe and results in interlobar cleft closure. These processes generate a fully active state of MPK38. This structure suggests that MPK38 has a similar molecular mechanism regulating activation as in other kinases of the SNF1/AMPK family.

scholarly journals AMPK/ULK1-mediated phosphorylation of Parkin ACT domain mediates an early step in mitophagy

2021 ◽  
Vol 7 (15) ◽  
pp. eabg4544
Author(s):  
Chien-Min Hung ◽  
Portia S. Lombardo ◽  
Nazma Malik ◽  
Sonja N. Brun ◽  
Kristina Hellberg ◽  
...  
Keyword(s):  
Ubiquitin Ligase ◽  
Phosphorylation Sites ◽  
Serine Threonine Kinase ◽  
Early Step ◽  
Threonine Kinase ◽  
The Core ◽  
Act Domain ◽  
Genetic Deletion ◽  
Cellular Stresses ◽  
Familial Parkinson’S Disease

The serine/threonine kinase ULK1 mediates autophagy initiation in response to various cellular stresses, and genetic deletion of ULK1 leads to accumulation of damaged mitochondria. Here we identify Parkin, the core ubiquitin ligase in mitophagy, and PARK2 gene product mutated in familial Parkinson’s disease, as a ULK1 substrate. Recent studies uncovered a nine residue (“ACT”) domain important for Parkin activation, and we demonstrate that AMPK-dependent ULK1 rapidly phosphorylates conserved serine108 in the ACT domain in response to mitochondrial stress. Phosphorylation of Parkin Ser108 occurs maximally within five minutes of mitochondrial damage, unlike activation of PINK1 and TBK1, which is observed thirty to sixty minutes later. Mutation of the ULK1 phosphorylation sites in Parkin, genetic AMPK or ULK1 depletion, or pharmacologic ULK1 inhibition, all lead to delays in Parkin activation and defects in assays of Parkin function and downstream mitophagy events. These findings reveal an unexpected first step in the mitophagy cascade.

Ability of PknA, a mycobacterial eukaryotic-type serine/threonine kinase, to transphosphorylate MurD, a ligase involved in the process of peptidoglycan biosynthesis

2008 ◽  
Vol 415 (1) ◽  
pp. 27-33 ◽  
Author(s):  
Meghna Thakur ◽  
Pradip K. Chakraborti
Keyword(s):  
Protein Kinases ◽  
Solid Phase ◽  
Morphological Changes ◽  
Binding Assays ◽  
Serine Threonine Kinase ◽  
Threonine Kinase ◽  
Peptidoglycan Biosynthesis ◽  
Vitro Binding ◽  
Solid Phase Binding

Eukaryotic-type serine/threonine protein kinases in bacteria have been implicated in controlling a host of cellular activities. PknA is one of eleven such protein kinases from Mycobacterium tuberculosis which regulates morphological changes associated with cell division. In the present study we provide the evidence for the ability of PknA to transphosphorylate mMurD (mycobacterial UDP-N-acetylmuramoyl-L-alanine:D-glutamate-ligase), the enzyme involved in peptidoglycan biosynthesis. Its co-expression in Escherichia coli along with PknA resulted in phosphorylation of mMurD. Consistent with these observations, results of the solid-phase binding assays revealed a high-affinity in vitro binding between the two proteins. Furthermore, overexpression of m-murD in Mycobacterium smegmatis yielded a phosphorylated protein. The results of the present study therefore point towards the possibility of mMurD being a substrate of PknA.

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