A type 5 acid phosphatase gene from Arabidopsis thaliana is induced by phosphate starvation and by some other types of phosphate mobilising/oxidative stress conditions

Mitochondrial heat shock proteins of HSP70 family support protein homeostasis in mitochondria under normal and stress conditions. They provide folding and complex assembly of proteins encoded by mitochondrial genome, as well as import of cytosolic proteins to mitochondria, their folding and protection against aggregation. There are reports about organ-specificity of mitochondrial HSP70 synthesis in plants. However, tissue specificity of their functioning remains incompletely characterized. This problem was studied for mitochondrial AtHSP70-10 in Arabidopsis thaliana seedlings using a transgenic line with uidA signal gene under normal conditions, as well as high temperature and water deficit. Under normal conditions, histochemical GUS-staining revealed the expression of AtHSP70-10 in cotyledon and leaf hydathodes, stipules, central cylinder in root differentiation and mature zones, as well as weak staining in root apex and root-shoot junction zone. RT-PCR analysis of wild-type seedlings exposed to 37°C showed rapid upregulation of AtHSP70-10, which reached the highest level within 2 h. In addition, the gradual development of water deficit for 5 days caused an increase in transcription of this gene, which became more pronounced after 3 days and reached a maximum after 5 days of dehydration. Histochemical analysis showed complete preservation of tissue localization of AtHSP70-10 expression under both abiotic factors. The data obtained indicate the specific functioning of mitochondrial chaperone AtHSP70-10 in certain plant cellular structures.

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Thiol-based switching mechanisms of stress-sensing chaperones

Biological Chemistry ◽

10.1515/hsz-2020-0262 ◽

2020 ◽

Vol 0 (0) ◽

Author(s):

Kathrin Ulrich ◽

Blanche Schwappach ◽

Ursula Jakob

Keyword(s):

Oxidative Stress ◽

Environmental Changes ◽

Stress Conditions ◽

Stress Exposure ◽

Atp Levels ◽

Protein Functions ◽

Activation Mechanisms ◽

Client Proteins ◽

Stress Sensing ◽

Redox Switches

AbstractThiol-based redox switches evolved as efficient post-translational regulatory mechanisms that enable individual proteins to rapidly respond to sudden environmental changes. While some protein functions need to be switched off to save resources and avoid potentially error-prone processes, protective functions become essential and need to be switched on. In this review, we focus on thiol-based activation mechanisms of stress-sensing chaperones. Upon stress exposure, these chaperones convert into high affinity binding platforms for unfolding proteins and protect cells against the accumulation of potentially toxic protein aggregates. Their chaperone activity is independent of ATP, a feature that becomes especially important under oxidative stress conditions, where cellular ATP levels drop and canonical ATP-dependent chaperones no longer operate. Vice versa, reductive inactivation and substrate release require the restoration of ATP levels, which ensures refolding of client proteins by ATP-dependent foldases. We will give an overview over the different strategies that cells evolved to rapidly increase the pool of ATP-independent chaperones upon oxidative stress and provide mechanistic insights into how stress conditions are used to convert abundant cellular proteins into ATP-independent holding chaperones.

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Arabidopsis thaliana and Oryza sativa receptor for activated C kinase 1 (RACK1) mediated signaling pathway shows hypersensitivity to oxidative stress

Plant Gene ◽

10.1016/j.plgene.2021.100299 ◽

2021 ◽

pp. 100299

Author(s):

Herman W.W. Fennell ◽

Hemayet Ullah ◽

Andre J. van Wijnen ◽

Eric A. Lewallen

Keyword(s):

Oxidative Stress ◽

Arabidopsis Thaliana ◽

Oryza Sativa ◽

Signaling Pathway

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Comparison of two Turnip mosaic virus P1 proteins in their ability to co-localize with the Arabidopsis thaliana G3BP-2 protein

Virus Genes ◽

10.1007/s11262-021-01829-w ◽

2021 ◽

Vol 57 (2) ◽

pp. 233-237

Author(s):

Hendrik Reuper ◽

Björn Krenz

Keyword(s):

Arabidopsis Thaliana ◽

Mosaic Virus ◽

Specific Interaction ◽

Viral Proteins ◽

Turnip Mosaic Virus ◽

Stress Conditions ◽

C Terminus ◽

Positive Sense ◽

Key Factor ◽

Large Host

AbstractTurnip mosaic virus (TuMV), belonging to the genus Potyvirus (family Potyviridae), has a large host range and consists of a single-stranded positive sense RNA genome encoding 12 proteins, including the P1 protease. This protein which is separated from the polyprotein by cis cleavage at its respective C-terminus, has been attributed with different functions during potyviral infection of plants. P1 of Turnip mosaic virus (P1-TuMV) harbors an FGSF-motif and FGSL-motif at its N-terminus. This motif is predicted to be a binding site for the host Ras GTPase-activating protein-binding protein (G3BP), which is a key factor for stress granule (SG) formation in mammalian systems and often targeted by viruses to inhibit SG formation. We therefore hypothesized that P1-TuMV might interact with G3BP to control and regulate plant SGs to optimize cellular conditions for the production of viral proteins. Here, we analyzed the co-localization of the Arabidopsis thaliana G3BP-2 with the P1 of two TuMV isolates, namely UK 1 and DEU 2. Surprisingly, P1-TuMV-DEU 2 co-localized with AtG3BP-2 under abiotic stress conditions, whereas P1-TuMV-UK 1 did not. AtG3BP-2::RFP showed strong SGs formation after stress, while P1-UK 1::eGFP maintained a chloroplastic signal under stress conditions, the signal of P1-DEU 2::eGFP co-localized with that of AtG3BP-2::RFP. This indicates a specific interaction between P1-DEU 2 and the AtG3BP family which is not solely based on the canonical interaction motifs.

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Modulation of chromatin structure associated with derepression of the acid phosphatase gene of Saccharomyces cerevisiae.

Journal of Biological Chemistry ◽

10.1016/s0021-9258(18)32355-x ◽

1983 ◽

Vol 258 (11) ◽

pp. 7223-7227

Author(s):

L W Bergman ◽

R A Kramer

Keyword(s):

Saccharomyces Cerevisiae ◽

Acid Phosphatase ◽

Chromatin Structure ◽

Acid Phosphatase Gene

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A manganese oxide nanozyme prevents the oxidative damage of biomolecules without affecting the endogenous antioxidant system

Nanoscale ◽

10.1039/c8nr09397k ◽

2019 ◽

Vol 11 (9) ◽

pp. 3855-3863 ◽

Cited By ~ 22

Author(s):

Namrata Singh ◽

Mohammed Azharuddin Savanur ◽

Shubhi Srivastava ◽

Patrick D'Silva ◽

Govindasamy Mugesh

Keyword(s):

Oxidative Stress ◽

Oxidative Damage ◽

Manganese Oxide ◽

Antioxidant System ◽

Mammalian Cells ◽

Redox State ◽

Stress Conditions ◽

System P ◽

Endogenous Antioxidant ◽

Antioxidant Machinery

Multi-enzyme mimetic Mn3O4 nanoflowers (Mp) modulate the redox state of mammalian cells without altering the cellular antioxidant machinery under oxidative stress conditions.

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