DAZL is essential for stress granule formation implicated in germ cell survival upon heat stress

AbstractThe NDR/LATS family kinases are a subclass of the AGC serine/threonine kinases which are important for morphogenesis and cell growth control. Using the model organismSchizosaccharomyces pombe, we previously reported that the NDR/LATS kinase Orb6 phosphorylates the RNA-binding protein (RBP) Sts5 serine 86 residue on its Intrinsically Disordered Domain (IDD). When dephosphorylated, Sts5 forms ribonucleoprotein (RNP) granules that colocalize with processing bodies (P-Bodies) and translationally repress mRNAs important for polarized cell growth. Here we report that Sts5 puncta colocalize with both P-Bodies and stress granules (SG) in response to glucose starvation, as well as heat, oxidative, and hyperosmotic stress. We find that loss of Sts5 decreases the number of stress granules, indicating that Sts5 has a role in promoting stress granule formation. Conversely, inhibition of Orb6 kinase promotes Sts5 aggregation and stress granule formation. In addition, loss of Sts5 decreases cell survival after heat stress, whereas decreasing Orb6 protein levels or including thests5S86Amutation, which promotes Sts5 aggregation, leads to increased survival. These data indicate that the Orb6-Sts5 axis is not only important for regulation of polarized growth but also for response to environmental stress, as dysregulation of the Orb6-Sts5 axis affects stress granule formation and cell survival.

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Ubiquitination is essential for recovery of cellular activities after heat shock

Science ◽

10.1126/science.abc3593 ◽

2021 ◽

Vol 372 (6549) ◽

pp. eabc3593

Author(s):

Brian A. Maxwell ◽

Youngdae Gwon ◽

Ashutosh Mishra ◽

Junmin Peng ◽

Haruko Nakamura ◽

...

Keyword(s):

Heat Stress ◽

Cultured Cells ◽

Nucleocytoplasmic Transport ◽

Stress Granule ◽

Eukaryotic Cells ◽

Granule Formation ◽

Cellular Processes ◽

Specific Proteins ◽

Global Increase ◽

As Stress

Eukaryotic cells respond to stress through adaptive programs that include reversible shutdown of key cellular processes, the formation of stress granules, and a global increase in ubiquitination. The primary function of this ubiquitination is thought to be for tagging damaged or misfolded proteins for degradation. Here, working in mammalian cultured cells, we found that different stresses elicited distinct ubiquitination patterns. For heat stress, ubiquitination targeted specific proteins associated with cellular activities that are down-regulated during stress, including nucleocytoplasmic transport and translation, as well as stress granule constituents. Ubiquitination was not required for the shutdown of these processes or for stress granule formation but was essential for the resumption of cellular activities and for stress granule disassembly. Thus, stress-induced ubiquitination primes the cell for recovery after heat stress.

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Ubiquitination is essential for recovery of cellular activities following heat shock

10.1101/2021.04.22.440934 ◽

2021 ◽

Author(s):

Brian A. Maxwell ◽

Youngdae Gwon ◽

Ashutosh Mishra ◽

Junmin Peng ◽

Ke Zhang ◽

...

Keyword(s):

Heat Stress ◽

Heat Shock ◽

Nucleocytoplasmic Transport ◽

Stress Granule ◽

Misfolded Proteins ◽

Eukaryotic Cells ◽

Granule Formation ◽

Cellular Processes ◽

Different Types ◽

Global Increase

AbstractEukaryotic cells respond to stress via adaptive programs that include reversible shutdown of key cellular processes, the formation of stress granules, and a global increase in ubiquitination. The primary function of this ubiquitination is generally considered to be tagging damaged or misfolded proteins for degradation. Here we show that different types of stress generate distinct ubiquitination patterns. For heat stress, ubiquitination correlates with cellular activities that are downregulated during stress, including nucleocytoplasmic transport and translation, as well as with stress granule constituents. Ubiquitination is not required for the shutdown of these processes or for stress granule formation, but is essential for resumption of cellular activities and for stress granule disassembly. These findings indicate that stress-induced ubiquitination primes the cell for recovery following heat stress.One Sentence SummaryStress-induced ubiquitination is essential for recovery of cellular activities following heat stress.

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Musashi-1 maintains blood–testis barrier structure during spermatogenesis and regulates stress granule formation upon heat stress

Molecular Biology of the Cell ◽

10.1091/mbc.e14-11-1497 ◽

2015 ◽

Vol 26 (10) ◽

pp. 1947-1956 ◽

Cited By ~ 10

Author(s):

Sun ErLin ◽

Wei WenJie ◽

Wang LiNing ◽

Lu BingXin ◽

Lei MingDe ◽

...

Keyword(s):

Heat Stress ◽

Cell Fate ◽

Sertoli Cell ◽

Sertoli Cells ◽

Stress Granules ◽

Stress Granule ◽

Granule Formation ◽

Associated Proteins ◽

Blood Testis Barrier

In mouse testes, Musashi-1 (Msi-1) was predominantly expressed in the cytoplasm and nuclei of Sertoli cells. Here we demonstrate that knockdown of Msi-1 in Sertoli cells altered the levels and distribution of blood–testis barrier (BTB)-associated proteins. Moreover, Msi-1 knockdown in vivo disrupted BTB functional structure and spermatogenesis. In addition, we report a novel role of Msi-1 in regulating Sertoli cells survival following heat-induced injury. Endogenous Msi-1 protein in heat-treated Sertoli cells was recruited to stress granules. The formation of stress granules was considerably disrupted, and apoptosis was significantly up-regulated in Msi-1–knockdown Sertoli cells after heat treatment. p-ERK1/2 acted downstream of stress granule formation, and inhibition of p-ERK1/2 signaling triggered Sertoli cell apoptosis upon heat stress. In conclusion, we demonstrate that Msi-1 is critical for constructing a functional BTB structure and maintaining spermatogenesis. We also note a role for Msi-1 in regulating Sertoli cell fate following heat-induced injury, likely through the induction of stress granule formation and subsequent activation of p-ERK1/2 signaling.

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Picornavirus 2A Protease Disrupts G3BP-eIF4GI Interaction That Initiates Typical Stress Granule Formation

SSRN Electronic Journal ◽

10.2139/ssrn.3155884 ◽

2018 ◽

Author(s):

Xiaodan Yang ◽

Zhulong Hu ◽

Shanshan Fan ◽

Qiang Zhang ◽

Yi Zhong ◽

...

Keyword(s):

Stress Granule ◽

Granule Formation ◽

2A Protease

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Polyhexamethylene guanidine phosphate, chloromethylisothiazolinone, and particulate matter are dispensable for stress granule formation in human airway epithelial cells

Animal Cells and Systems ◽

10.1080/19768354.2021.1931442 ◽

2021 ◽

pp. 1-6

Author(s):

Arnoldo Cambronero-Urena ◽

Sunkyung Choi ◽

Seri Choi ◽

Kee K. Kim ◽

Eun-Mi Kim

Keyword(s):

Particulate Matter ◽

Epithelial Cells ◽

Airway Epithelial Cells ◽

Stress Granule ◽

Airway Epithelial ◽

Granule Formation ◽

Human Airway ◽

Polyhexamethylene Guanidine ◽

Guanidine Phosphate ◽

Human Airway Epithelial Cells

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Interaction of TIA-1/TIAR with West Nile and dengue virus products in infected cells interferes with stress granule formation and processing body assembly

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.0703348104 ◽

2007 ◽

Vol 104 (21) ◽

pp. 9041-9046 ◽

Cited By ~ 195

Author(s):

M. M. Emara ◽

M. A. Brinton

Keyword(s):

Dengue Virus ◽

Stress Granule ◽

West Nile ◽

Granule Formation ◽

Infected Cells ◽

Processing Body

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The Leader Protein of Theiler's Virus Prevents the Activation of PKR

Journal of Virology ◽

10.1128/jvi.01010-19 ◽

2019 ◽

Vol 93 (19) ◽

Cited By ~ 4

Author(s):

Fabian Borghese ◽

Frédéric Sorgeloos ◽

Teresa Cesaro ◽

Thomas Michiels

Keyword(s):

Stress Granule ◽

Translation Initiation Factor ◽

Initiation Factor ◽

Wild Type Virus ◽

Granule Formation ◽

Double Stranded Rna ◽

Eif2α Phosphorylation ◽

Leader Protein ◽

Infected Cells ◽

L Proteins

ABSTRACT Leader (L) proteins encoded by cardioviruses are multifunctional proteins that contribute to innate immunity evasion. L proteins of Theiler’s murine encephalomyelitis virus (TMEV), Saffold virus (SAFV), and encephalomyocarditis virus (EMCV) were reported to inhibit stress granule assembly in infected cells. Here, we show that TMEV L can act at two levels in the stress granule formation pathway: on the one hand, it can inhibit sodium arsenite-induced stress granule assembly without preventing eIF2α phosphorylation and, thus, acts downstream of eIF2α; on the other hand, it can inhibit eucaryotic translation initiation factor 2 alpha kinase 2 (PKR) activation and the consequent PKR-mediated eIF2α phosphorylation. Interestingly, coimmunostaining experiments revealed that PKR colocalizes with viral double-stranded RNA (dsRNA) in cells infected with L-mutant viruses but not in cells infected with the wild-type virus. Furthermore, PKR coprecipitated with dsRNA from cells infected with L-mutant viruses significantly more than from cells infected with the wild-type virus. These data strongly suggest that L blocks PKR activation by preventing the interaction between PKR and viral dsRNA. In infected cells, L also rendered PKR refractory to subsequent activation by poly(I·C). However, no interaction was observed between L and either dsRNA or PKR. Taken together, our results suggest that, unlike other viral proteins, L indirectly acts on PKR to negatively regulate its responsiveness to dsRNA. IMPORTANCE The leader (L) protein encoded by cardioviruses is a very short multifunctional protein that contributes to evasion of the host innate immune response. This protein notably prevents the formation of stress granules in infected cells. Using Theiler’s virus as a model, we show that L proteins can act at two levels in the stress response pathway leading to stress granule formation, the most striking one being the inhibition of eucaryotic translation initiation factor 2 alpha kinase 2 (PKR) activation. Interestingly, the leader protein appears to inhibit PKR via a novel mechanism by rendering this kinase unable to detect double-stranded RNA, its typical activator. Unlike other viral proteins, such as influenza virus NS1, the leader protein appears to interact with neither PKR nor double-stranded RNA, suggesting that it acts indirectly to trigger the inhibition of the kinase.

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Puumala and Andes Orthohantaviruses Cause Transient Protein Kinase R-Dependent Formation of Stress Granules

Journal of Virology ◽

10.1128/jvi.01168-19 ◽

2019 ◽

Vol 94 (3) ◽

Cited By ~ 4

Author(s):

Wanda Christ ◽

Janne Tynell ◽

Jonas Klingström

Keyword(s):

Protein Kinase ◽

Host Cell ◽

Stress Responses ◽

Stress Granules ◽

Cell Stress ◽

Stress Granule ◽

Hantavirus Infection ◽

Stress Signaling ◽

Protein Kinase R ◽

Granule Formation

ABSTRACT Virus infection frequently triggers host cell stress signaling resulting in translational arrest; as a consequence, many viruses employ means to modulate the host stress response. Hantaviruses are negative-sense, single-stranded RNA viruses known to inhibit host innate immune responses and apoptosis, but their impact on host cell stress signaling remains largely unknown. In this study, we investigated activation of host cell stress responses during hantavirus infection. We show that hantavirus infection causes transient formation of stress granules (SGs) but does so in only a limited proportion of infected cells. Our data indicate some cell type-specific and hantavirus species-specific variability in SG prevalence and show SG formation to be dependent on the activation of protein kinase R (PKR). Hantavirus infection inhibited PKR-dependent SG formation, which could account for the transient nature and low prevalence of SG formation observed during hantavirus infection. In addition, we report only limited colocalization of hantaviral proteins or RNA with SGs and show evidence indicating hantavirus-mediated inhibition of PKR-like endoplasmic reticulum (ER) kinase (PERK). IMPORTANCE Our work presents the first report on stress granule formation during hantavirus infection. We show that hantavirus infection actively inhibits stress granule formation, thereby escaping the detrimental effects on global translation imposed by host stress signaling. Our results highlight a previously uncharacterized aspect of hantavirus-host interactions with possible implications for how hantaviruses are able to cause persistent infection in natural hosts and for pathogenesis.

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