scholarly journals The cryo-EM structure of the chloroplast ClpP complex reveals an interaction with the co-chaperonin complex that inhibits ClpP proteolytic activity

2021 ◽  
Author(s):  
Ning Wang ◽  
Yifan Wang ◽  
Qian Zhao ◽  
Xiang Zhang ◽  
Chao Peng ◽  
...  
Keyword(s):  
Quality Control ◽  
Protein Folding ◽  
Control System ◽  
Proteolytic Activity ◽  
Protease Activity ◽  
Protein Quality ◽  
Protein Homeostasis ◽  
Clp Protease ◽  
Protein Quality Control System

Protein homeostasis in plastids is strategically regulated by the protein quality control system involving multiple chaperones and proteases, among them the Clp protease. We determined the structure of the chloroplast ClpP complex from Chlamydomonas reinhardtiiby cryo-EM. ClpP contains two heptameric catalytic rings without any symmetry. The top ring contains one ClpR6, three ClpP4 and three ClpP5 subunits while the bottom ring is composed of three ClpP1C subunits and one each of the ClpR1-4 subunits. ClpR3, ClpR4 and ClpT4 subunits connect the two rings and stabilize the complex. The chloroplast Cpn11/20/23 co-chaperonin, a co-factor of Cpn60, forms a cap on the top of ClpP by protruding mobile loops into hydrophobic clefts at the surface of the top ring. The co-chaperonin repressed ClpP proteolytic activity in vitro. By regulating Cpn60 chaperone and ClpP protease activity, the co-chaperonin may play a role in coordinating protein folding and degradation in the chloroplast.

Direct evidence of cytosolic PNGase activity in Arabidopsis thaliana: in vitro assay system for plant cPNGase activity

2021 ◽  
Author(s):  
Sahoko Shirai ◽  
Ryota Uemura ◽  
Megumi Maeda ◽  
Hiroyuki Kajiura ◽  
Ryo Misaki ◽  
...  
Keyword(s):  
Quality Control ◽  
Arabidopsis Thaliana ◽  
Control System ◽  
Direct Evidence ◽  
Protein Quality ◽  
In Vitro Assay ◽  
Eukaryotic Cells ◽  
Vitro Assay ◽  
Protein Quality Control System

Abstract Cytosolic peptide: N-glycanase (cPNGase), which occurs ubiquitously in eukaryotic cells, is involved in the de-N-glycosylation of misfolded glycoproteins in the protein quality control system. In this study, we aimed to provide direct evidence of plant cPNGase activity against a denatured glycoprotein using a crude extract prepared from a mutant line of Arabidopsis thaliana lacking two acidic PNGase genes.

scholarly journals A Crucial Role for the Protein Quality Control System in Motor Neuron Diseases

2020 ◽  
Vol 12 ◽  
Author(s):  
Riccardo Cristofani ◽  
Valeria Crippa ◽  
Maria Elena Cicardi ◽  
Barbara Tedesco ◽  
Veronica Ferrari ◽  
...  
Keyword(s):  
Quality Control ◽  
Control System ◽  
Motor Neuron ◽  
Crucial Role ◽  
Protein Quality ◽  
Protein Quality Control ◽  
Quality Control System ◽  
Motor Neuron Diseases ◽  
Protein Quality Control System

scholarly journals Roles and Mechanisms of the Protein Quality Control System in Alzheimer’s Disease

2021 ◽  
Vol 23 (1) ◽  
pp. 345
Author(s):  
Yaping Liu ◽  
Runrong Ding ◽  
Ze Xu ◽  
Yuan Xue ◽  
Dongdong Zhang ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Quality Control ◽  
Control System ◽  
Protein Quality ◽  
Early Stage ◽  
Senile Plaques ◽  
Protein Quality Control ◽  
Quality Control System ◽  
Protein Quality Control System

Alzheimer’s disease (AD) is characterized by the deposition of senile plaques (SPs) and the formation of neurofibrillary tangles (NTFs), as well as neuronal dysfunctions in the brain, but in fact, patients have shown a sustained disease progression for at least 10 to 15 years before these pathologic biomarkers can be detected. Consequently, as the most common chronic neurological disease in the elderly, the challenge of AD treatment is that it is short of effective biomarkers for early diagnosis. The protein quality control system is a collection of cellular pathways that can recognize damaged proteins and thereby modulate their turnover. Abundant evidence indicates that the accumulation of abnormal proteins in AD is closely related to the dysfunction of the protein quality control system. In particular, it is the synthesis, degradation, and removal of essential biological components that have already changed in the early stage of AD, which further encourages us to pay more attention to the protein quality control system. The review mainly focuses on the endoplasmic reticulum system (ERS), autophagy–lysosome system (ALS) and the ubiquitin–proteasome system (UPS), and deeply discusses the relationship between the protein quality control system and the abnormal proteins of AD, which can not only help us to understand how and why the complex regulatory system becomes malfunctional during AD progression, but also provide more novel therapeutic strategies to prevent the development of AD.

scholarly journals Intrinsic disorder codes for leaps of protein expression

2020 ◽  
Author(s):  
Chi-Ning Chuang ◽  
Tai-Ting Woo ◽  
Shih-Ying Tsai ◽  
Wan-Chen Li ◽  
Chia-Ling Chen ◽  
...  
Keyword(s):  
Quality Control ◽  
Protein Folding ◽  
Protein Expression ◽  
Posttranslational Modifications ◽  
Protein Quality ◽  
Intrinsic Disorder ◽  
Protein Homeostasis ◽  
Intrinsically Disordered ◽  
Intrinsically Disordered Regions ◽  
Regulate Protein

AbstractIntrinsically disordered regions (IDRs) are protein sequences lacking fixed or ordered three-dimensional structures. Many IDRs are endowed with important molecular functions such as physical interactions, posttranslational modifications or solubility enhancement. We reveal that several biologically important IDRs can act as N-terminal fusion carriers to promote target protein folding or protein quality control, thereby enhancing protein expression. This nanny function has a reasonably strong correlation with high S/T/Q/N amino acid content in IDRs and it is tunable (e.g., via phosphorylation) to regulate protein homeostasis. We propose a hypothesis that “N-terminal intrinsic disorder facilitates abundance” (NIDFA) to explain how some yeast proteins use their N-terminal IDRs (N-IDRs) to generate high levels of protein product. These N-IDRs are versatile toolkits for functional divergence in signaling and evolution.SignificanceDisorder within an otherwise well-structured protein is mostly found in intrinsically disordered regions (IDRs). IDRs can provide many advantages to proteins, including: (1) mediating protein-protein or protein-peptide interactions by adopting different conformations; (2) facilitating protein regulation via diverse posttranslational modifications; and (3) regulating the half-lives of proteins that have been targeted for proteasomal degradation. Here, we report that several biologically important IDRs in S. cerevisiae can act as N-terminal fusion carriers to promote target protein folding or protein quality control, thereby enhancing protein expression. We demonstrate by genetic and bioinformatic analyses that this nanny function is well correlated with high content of serine, threonine, glutamine and asparagine in IDRs and is tunable (e.g., via phosphorylation) to regulate protein homeostasis.

Components of the protein quality control system are expressed in a strain-dependent manner in the mouse hippocampus

2006 ◽  
Vol 49 (5) ◽  
pp. 500-507 ◽  
Author(s):  
Daniela D. Pollak ◽  
Julius John ◽  
Hermann Bubna-Littitz ◽  
Angela Schneider ◽  
Harald Hoeger ◽  
...  
Keyword(s):  
Quality Control ◽  
Control System ◽  
Protein Quality ◽  
Protein Quality Control ◽  
Quality Control System ◽  
Dependent Manner ◽  
Mouse Hippocampus ◽  
Protein Quality Control System ◽  
Strain Dependent
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