scholarly journals The control of inflammation via the phosphorylation and dephosphorylation of tristetraprolin: a tale of two phosphatases

2016 ◽  
Vol 44 (5) ◽  
pp. 1321-1337 ◽  
Author(s):  
Andrew R. Clark ◽  
Jonathan L.E. Dean

Twenty years ago, the first description of a tristetraprolin (TTP) knockout mouse highlighted the fundamental role of TTP in the restraint of inflammation. Since then, work from several groups has generated a detailed picture of the expression and function of TTP. It is a sequence-specific RNA-binding protein that orchestrates the deadenylation and degradation of several mRNAs encoding inflammatory mediators. It is very extensively post-translationally modified, with more than 30 phosphorylations that are supported by at least two independent lines of evidence. The phosphorylation of two particular residues, serines 52 and 178 of mouse TTP (serines 60 and 186 of the human orthologue), has profound effects on the expression, function and localisation of TTP. Here, we discuss the control of TTP biology via its phosphorylation and dephosphorylation, with a particular focus on recent advances and on questions that remain unanswered.

FEBS Open Bio ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 1964-1976 ◽  
Author(s):  
Nirmala Tilija Pun ◽  
Amrita Khakurel ◽  
Aastha Shrestha ◽  
Sang‐Hyun Kim ◽  
Pil‐Hoon Park

Author(s):  
Masashi Yukawa ◽  
Mitsuki Ohishi ◽  
Yusuke Yamada ◽  
Takashi Toda

Cells form a bipolar spindle during mitosis to ensure accurate chromosome segregation. Proper spindle architecture is established by a set of kinesin motors and microtubule-associated proteins. In most eukaryotes, kinesin-5 motors are essential for this process, and genetic or chemical inhibition of their activity leads to the emergence of monopolar spindles and cell death. However, these deficiencies can be rescued by simultaneous inactivation of kinesin-14 motors, as they counteract kinesin-5. We conducted detailed genetic analyses in fission yeast to understand the mechanisms driving spindle assembly in the absence of kinesin-5. Here we show that deletion of the nrp1 gene, which encodes a putative RNA-binding protein with unknown function, can rescue temperature sensitivity caused by cut7-22, a fission yeast kinesin-5 mutant. Interestingly, kinesin-14/Klp2 levels on the spindles in the cut7 mutants were significantly reduced by the nrp1 deletion, although the total levels of Klp2 and the stability of spindle microtubules remained unaffected. Moreover, RNA-binding motifs of Nrp1 are essential for its cytoplasmic localization and function. We have also found that a portion of Nrp1 is spatially and functionally sequestered by chaperone-based protein aggregates upon mild heat stress and limits cell division at high temperatures. We propose that Nrp1 might be involved in post-transcriptional regulation through its RNA-binding ability to promote the loading of Klp2 on the spindle microtubules.


2010 ◽  
Vol 24 (S1) ◽  
Author(s):  
Weibin Zha ◽  
Guangji Wang ◽  
Beth S. Pecora ◽  
Elaine Studer ◽  
Phillip B Hylemon ◽  
...  

2010 ◽  
Vol 222 (3) ◽  
pp. 223-226 ◽  
Author(s):  
David J Elliott ◽  
Prabhakar Rajan

2020 ◽  
Vol 78 (1) ◽  
Author(s):  
Sajad Rashidi ◽  
Kurosh Kalantar ◽  
Celia Fernandez-Rubio ◽  
Enayat Anvari ◽  
Paul Nguewa ◽  
...  

ABSTRACT Leishmaniasis includes a broad spectrum of pathological outcomes in humans caused by protozoan parasites from the genus Leishmania. In recent years, proteomic techniques have introduced novel proteins with critical functions in Leishmania parasites. Based on our report of a Chitin binding protein (CBP) in our previous immunoproteomic study, this article suggests that CBP might be an RNA binding protein (RBP) in Leishmania parasites. RBPs, as key regulatory factors, have a role in post-transcriptional gene regulation. The presence of RBPs in Leishmania parasites has not been considered so far; however, this study aims to open a new venue regarding RBPs in Leishmania parasites. Confirming CBP as an RBP in Leishmania parasites, exploring other RBPs and their functions might lead to interesting issues in leishmaniasis. In fact, due to the regulatory role of RBPs in different diseases including cancers and their further classification as therapeutic targets, the emerging evaluation of CBP and RBPs from Leishmania parasites may allow the discovery of novel and effective drugs against leishmaniasis.


2004 ◽  
Vol 186 (11) ◽  
pp. 3355-3362 ◽  
Author(s):  
Janne K. Christiansen ◽  
Marianne H. Larsen ◽  
Hanne Ingmer ◽  
Lotte Søgaard-Andersen ◽  
Birgitte H. Kallipolitis

ABSTRACT In gram-negative bacteria, the RNA-binding protein Hfq has emerged as an important regulatory factor in a variety of physiological processes, including stress resistance and virulence. In Escherichia coli, Hfq modulates the stability or the translation of mRNAs and interacts with numerous small regulatory RNAs. Here, we studied the role of Hfq in the stress tolerance and virulence of the gram-positive food-borne human pathogen Listeria monocytogenes. We present evidence that Hfq is involved in the ability of L. monocytogenes to tolerate osmotic and ethanol stress and contributes to long-term survival under amino acid-limiting conditions. However, Hfq is not required for resistance to acid and oxidative stress. Transcription of hfq is induced under various stress conditions, including osmotic and ethanol stress and at the entry into the stationary growth phase, thus supporting the view that Hfq is important for the growth and survival of L. monocytogenes in harsh environments. The stress-inducible transcription of hfq depends on the alternative sigma factor σB, which controls the expression of numerous stress- and virulence-associated genes in L. monocytogenes. Infection studies showed that Hfq contributes to pathogenesis in mice, yet plays no role in the infection of cultured cell lines. This study provides, for the first time, information on the role of Hfq in the stress tolerance and virulence of a gram-positive pathogen.


BioEssays ◽  
1996 ◽  
Vol 18 (3) ◽  
pp. 191-198 ◽  
Author(s):  
Edward Chu ◽  
Carmen J. Allegra

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