Effects of light and temperature on expression of ClpC, the regulatory subunit of chloroplastic Clp protease, in pea seedlings

1996 ◽  
Vol 31 (3) ◽  
pp. 673-676 ◽  
Author(s):  
Oren Ostersetzer ◽  
Zach Adam
Keyword(s):  
Regulatory Subunit ◽  
Clp Protease ◽  
Pea Seedlings

scholarly journals Degradation of Abnormal Proteins in Chloroplasts of Higher Plants

1994 ◽  
Author(s):  
Zach Adam ◽  
Eran Pichersky
Keyword(s):  
Higher Plants ◽  
Chimeric Protein ◽  
Degradation Process ◽  
Regulatory Subunit ◽  
Clp Protease ◽  
Ftsh Protease ◽  
Arabidopsis Mutant ◽  
Turn Over

In this study we attempted to get a better understanding of processes involved in the degradation of abnormal proteins i chloroplasts. To achieve this goal, we used a number of complementary approaches. We first characterized the expression of the two subunits of Clp protease. We demonstrated that both of them were expressed in chloroplasts in a constitutive fashion, but the expression of the regulatory subunit ClpC was enhanced by light. We generated a mutant the lumenal protein OEE33 which was targeted to the stroma in in vitro experiments. In the wrong compartment it was found unstable, and characterization of its degradation revealed that it was degraded by a soluble, ATP-dependent serine protease, which are also the characteristics of Clp protease. In search of other homologues of bacterial proteases, we found that chloroplasts contain a homologue of the FtsH protease. It is an ATP-dependent metallo-protease, bound to the stromal side of the thylakoid membrane, whose expression is dependent on light. The gene encodig this protease was cloned and characterized. In attempt to generate Arabidopsis mutant plants impaired in their capability to degrade abnormal chloroplast proteins, we fused the gene for mistargeted OEE33 to the streptomycin-detoxifying gene. This chimeric gene was introduced into Arabodipsis plants, to generate transformed plants. This transformants plants were sensitive to streptomycin due to the rapid turn-over of the chimeric protein. Seeds from these plants were then chemically mutagenised, and seedlings were selected for their capability to grow on streptomycin. The ability of these mutant transformants to grow on streptomycin is presumably due to stabilization of the chimeric protein. These plants will allow us in the future to identify the effected genes, which are likely to be involved in the protein degradation process.

Expression and mutation analysis of regulatory subunit Iα of protein kinase A in undifferentiated and anaplastic thyroid carcinoma

2004 ◽  
Vol 112 (S 1) ◽  
Author(s):  
M Lippert ◽  
SY Sheu ◽  
K Worm ◽  
M Wichert ◽  
KW Schmid ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Thyroid Carcinoma ◽  
Protein Kinase A ◽  
Mutation Analysis ◽  
Anaplastic Thyroid Carcinoma ◽  
Regulatory Subunit ◽  
Kinase A

Sequence of the human glycogen-associated regulatory subunit of type 1 protein phosphatase and analysis of its coding region and mRNA level in muscle from patients with NIDDM

Diabetes ◽  
1994 ◽  
Vol 43 (10) ◽  
pp. 1234-1241 ◽  
Author(s):  
Y. H. Chen ◽  
L. Hansen ◽  
M. X. Chen ◽  
C. Bjorbaek ◽  
H. Vestergaard ◽  
...  
Keyword(s):  
Protein Phosphatase ◽  
Mrna Level ◽  
Regulatory Subunit ◽  
Coding Region

TAp73 opposes tumor angiogenesis by promoting hypoxia-inducible factor 1α degradation

2020 ◽  
Author(s):  
Lungwani Muungo
Keyword(s):  
Cancer Progression ◽  
Hypoxia Inducible Factor ◽  
Tumor Hypoxia ◽  
Human Lung Cancer ◽  
Regulatory Subunit ◽  
Patients With Cancer ◽  
Hypoxia Inducible Factor 1 ◽  
Chemically Induced ◽  
Induced Tumors ◽  
Patient Prognosis

Tumor hypoxia and hypoxia-inducible factor 1 (HIF-1) activationare associated with cancer progression. Here, we demonstrate thatthe transcription factor TAp73 opposes HIF-1 activity through anontranscriptional mechanism, thus affecting tumor angiogenesis.TAp73-deficient mice have an increased incidence of spontaneousand chemically induced tumors that also display enhanced vascularization.Mechanistically, TAp73 interacts with the regulatory subunit(α) of HIF-1 and recruits mouse double minute 2 homolog intothe protein complex, thus promoting HIF-1α polyubiquitination andconsequent proteasomal degradation in an oxygen-independentmanner. In human lung cancer datasets, TAp73 strongly predictsgood patient prognosis, and its expression is associated with lowHIF-1 activation and angiogenesis. Our findings, supported by invivo and clinical evidence, demonstrate a mechanism for oxygenindependentHIF-1 regulation, which has important implicationsfor individualizing therapies in patients with cancer.

Sign in / Sign up

Export Citation Format

Share Document