Faculty Opinions recommendation of Functional characterization of pkr gene products expressed in cells from mice with a targeted deletion of the N terminus or C terminus domain of PKR.

The Saccharomyces cerevisiae Ste11p protein kinase is a homologue of mammalian MAPK/extracellular signal-regulated protein kinase kinase kinases (MAPKKKs or MEKKs) as well as theSchizosaccharomyces pombe Byr2p kinase. Ste11p functions in several signaling pathways, including those for mating pheromone response and osmotic stress response. The Ste11p kinase has an N-terminal domain that interacts with other signaling molecules to regulate Ste11p function and direct its activity in these pathways. One of the Ste11p regulators is Ste50p, and Ste11p and Ste50p associate through their respective N-terminal domains. This interaction relieves a negative activity of the Ste11p N terminus, and removal of this negative function is required for Ste11p function in the high-osmolarity glycerol (HOG) pathway. The Ste50p/Ste11p interaction is also important (but not essential) for Ste11p function in the mating pathway; in this pathway binding of the Ste11p N terminus with both Ste50p and Ste5p is required, with the Ste5p association playing the major role in Ste11p function. In vitro, Ste50p disrupts an association between the catalytic C terminus and the regulatory N terminus of Ste11p. In addition, Ste50p appears to modulate Ste11p autophosphorylation and is itself a substrate of the Ste11p kinase. Therefore, both in vivo and in vitro data support a role for Ste50p in the regulation of Ste11p activity.

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A phospho-switch in the N-terminus of NRT2.1 affects nitrate uptake by controlling the interaction of NRT2.1 with NAR2.1

10.1101/2020.01.08.898254 ◽

2020 ◽

Cited By ~ 1

Author(s):

Zhi Li ◽

Xu Na Wu ◽

Aurore Jaquot ◽

Larence Lejay ◽

Waltraud X Schulze

Keyword(s):

Nitrate Uptake ◽

Functional Characterization ◽

Kinase Domain ◽

Data Sets ◽

C Terminus ◽

N Terminus ◽

Switch Mechanism ◽

A Site ◽

Nitrate Starvation

AbstractNRT2.1 can be phosphorylated at five different sites within N- and C-terminus. Here, we provide a systematic functional characterization of phosphorylation at S21 and S28 within the N-terminus of NRT2.1. We used existing phosphoproteomic data sets of nitrate starvation and nitrate resupply to construct a site-specific correlation network identifying kinase candidates to phosphorylate NRT2.1. By this approach, we identified NITRATE UPTAKE REGULATORY KINASE 1 (AT5G49770) which itself was regulated by phosphorylation at S839 and S870 within its kinase domain. In the active state, when S839 was dephosphorylated and S870 was phosphorylated, NURK1 was found to interact with NRT2.1 at dephosphorylated S28. Upon that interaction, NURK1 can phosphorylate NRT2.1 at S21. Phosphorylation of NRT2.1 at S21 resulted in low interaction of NRT2.1 with its activator protein NAR2.1. By contrast, phosphorylation of NRT2.1 at S28 by a yet unknown kinase enhanced the interaction with NAR2.1, but inhibited the interaction with NURK1. We propose that serines S21 and S28 are involved in a phospho-switch mechanism and by which the interaction of NRT2.1 with its activator NAR2.1, and thus NRT2.1 activity, is modulated. NURK1 here was identified as the kinase affecting this phospho-switch through phosphorylation of NRT2.1 at S21 leading to inactivation of NRT2.1.

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Characterization of four new monoclonal antibodies against the distal N-terminal region of PrPc

10.7287/peerj.preprints.694 ◽

2014 ◽

Author(s):

Alessandro Didonna ◽

Anja Colja Venturini ◽

Katrina Hartman ◽

Tanja Vranac ◽

Vladka Curin Serbec ◽

...

Keyword(s):

Monoclonal Antibodies ◽

Prion Protein ◽

Biochemical Characterization ◽

Prion Diseases ◽

Physiological Role ◽

Prion Infection ◽

Promising Tool ◽

C Terminus ◽

N Terminus

Prion diseases are a group of fatal neurodegenerative disorders that affect humans and animals. They are characterized by the accumulation in the central nervous system of a pathological form of the host-encoded prion protein (PrPC). The prion protein is a membrane glycoprotein that consists of two domains: a globular, structured C-terminus and an unstructured N-terminus. The N-terminal part of the protein is involved in different functions in both health and disease. In the present work we discuss the production and biochemical characterization of a panel of four monoclonal antibodies (mAbs) against the distal N-terminus of PrPC using a well-established methodology based on the immunization of Prnp0/0 mice. Additionally, we show their ability to block prion (PrPSc) replication at nanomolar concentrations in a cell culture model of prion infection. These mAbs represent a promising tool for prion diagnostics and for studying the physiological role of the N-terminal domain of PrPC.

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Functional Characterization of the C-Terminus of YhaV in the Escherichia coli PrlF-YhaV Toxin-Antitoxin System

Journal of Microbiology and Biotechnology ◽

10.4014/jmb.1803.03010 ◽

2018 ◽

Vol 28 (6) ◽

pp. 987-996 ◽

Cited By ~ 2

Author(s):

Wonho Choi ◽

Min-Ho Yoon ◽

Jung-Ho Park

Keyword(s):

Escherichia Coli ◽

Functional Characterization ◽

C Terminus

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Structural and Functional Characterization of Gene Products Encoded in the Human Genome by Homology Detection

IUBMB Life ◽

10.1080/15216540400006105 ◽

2004 ◽

Vol 56 (6) ◽

pp. 317-331 ◽

Cited By ~ 5

Author(s):

Pandit SB ◽

Balaji S ◽

Srinivasan N

Keyword(s):

Human Genome ◽

Functional Characterization ◽

Gene Products ◽

Homology Detection

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Characterization of hybrid proteins consisting of the catalytic domains of Clostridium and Ruminococcus endoglucanases, fused to Pseudomonas non-catalytic cellulose-binding domains

Biochemical Journal ◽

10.1042/bj2790787 ◽

1991 ◽

Vol 279 (3) ◽

pp. 787-792 ◽

Cited By ~ 22

Author(s):

D M Poole ◽

A J Durrant ◽

G P Hazlewood ◽

H J Gilbert

Keyword(s):

Catalytic Domain ◽

Binding Capacity ◽

Binding Domains ◽

Hybrid Proteins ◽

C Terminus ◽

N Terminus ◽

Fusion Enzymes ◽

Cellulose Binding

The N-terminal 160 or 267 residues of xylanase A from Pseudomonas fluorescens subsp. cellulosa, containing a non-catalytic cellulose-binding domain (CBD), were fused to the N-terminus of the catalytic domain of endoglucanase E (EGE') from Clostridium thermocellum. A further hybrid enzyme was constructed consisting of the 347 N-terminal residues of xylanase C (XYLC) from P. fluorescens subsp. cellulosa, which also constitutes a CBD, fused to the N-terminus of endoglucanase A (EGA) from Ruminococcus albus. The three hybrid enzymes bound to insoluble cellulose, and could be eluted such that cellulose-binding capacity and catalytic activity were retained. The catalytic properties of the fusion enzymes were similar to EGE' and EGA respectively. Residues 37-347 and 34-347 of XYLC were fused to the C-terminus of EGE' and the 10 amino acids encoded by the multiple cloning sequence of pMTL22p respectively. The two hybrid proteins did not bind cellulose, although residues 39-139 of XYLC were shown previously to constitute a functional CBD. The putative role of the P. fluorescens subsp. cellulosa CBD in cellulase action is discussed.

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