scholarly journals The Involvement of Ubiquitination Machinery in Cell Cycle Regulation and Cancer Progression

2021 ◽  
Vol 22 (11) ◽  
pp. 5754
Author(s):  
Tingting Zou ◽  
Zhenghong Lin

The cell cycle is a collection of events by which cellular components such as genetic materials and cytoplasmic components are accurately divided into two daughter cells. The cell-cycle transition is primarily driven by the activation of cyclin-dependent kinases (CDKs), the activities of which are regulated by the ubiquitin-mediated proteolysis of key regulators such as cyclins and CDK inhibitors (CKIs). Thus, the ubiquitin-proteasome system (UPS) plays a pivotal role in the regulation of the cell-cycle process via recognition, interaction, and ubiquitination or deubiquitination of key proteins. The illegitimate degradation of tumor suppressor proteins and oncoproteins or, inversely, abnormally high accumulation results in cell proliferation deregulation, genomic instability, and cancer occurrence. In this review, we demonstrate the diversity and complexity of the UPS machinery regulation of the cell cycle. A profound understanding of the ubiquitination machinery will provide new insights into the regulation of the cell-cycle transition, cancer treatment, and the development of anti-cancer drugs.

Molecules ◽  
2021 ◽  
Vol 26 (18) ◽  
pp. 5606
Author(s):  
Laura Márquez-Cantudo ◽  
Ana Ramos ◽  
Claire Coderch ◽  
Beatriz de Pascual-Teresa

Protein degradation by the Ubiquitin-Proteasome System is one of the main mechanisms of the regulation of cellular proteostasis, and the E3 ligases are the key effectors for the protein recognition and degradation. Many E3 ligases have key roles in cell cycle regulation, acting as checkpoints and checkpoint regulators. One of the many important proteins involved in the regulation of the cell cycle are the members of the Histone Deacetylase (HDAC) family. The importance of zinc dependent HDACs in the regulation of chromatin packing and, therefore, gene expression, has made them targets for the design and synthesis of HDAC inhibitors. However, achieving potency and selectivity has proven to be a challenge due to the homology between the zinc dependent HDACs. PROteolysis TArgeting Chimaera (PROTAC) design has been demonstrated to be a useful strategy to inhibit and selectively degrade protein targets. In this review, we attempt to summarize the E3 ligases that naturally ubiquitinate HDACs, analyze their structure, and list the known ligands that can bind to these E3 ligases and be used for PROTAC design, as well as the already described HDAC-targeted PROTACs.


2005 ◽  
Vol 41 ◽  
pp. 187-203 ◽  
Author(s):  
Anny Devoy ◽  
Tim Soane ◽  
Rebecca Welchman ◽  
R. John Mayer

The ubiquitin proteasome system (UPS) has emerged from obscurity to be seen as a major player in all regulatory processes in the cell. The concentrations of key proteins in diverse regulatory pathways are controlled by post-translational ubiquitination and degradation by the 26 S proteasome. These regulatory cascades include growth-factor-controlled signal-transduction pathways and multiple points in the cell cycle. The cell cycle is orchestrated by a combination of cyclin-dependent kinases, kinase inhibitors and protein phosphorylation, together with the timely and specific degradation of cyclins and kinase inhibitors at critical points in the cell cycle by the UPS. These processes provide the irreversibility needed for movement of the cycle through gap 1 (G1), DNA synthesis (S), gap 2 (G2) and mitosis (M). The molecular events include cell-size control, DNA replication, DNA repair, chromosomal rearrangements and cell division. It is doubtful whether these events could be achieved without the temporally and spatially regulated combination of protein phosphorylation and ubiquitin-dependent degradation of key cell-cycle regulatory proteins. The oncogenic transformation of cells is a multistep process that can be triggered by mutation of genes for proteins involved in regulatory processes from the cell surface to the nucleus. Since the UPS has critical functions at all these levels of control, it is to be expected that UPS activities will be central to cell transformation and cancer progression.


2013 ◽  
Vol 31 (9) ◽  
pp. 1231-1238 ◽  
Author(s):  
Lindsey N. Micel ◽  
John J. Tentler ◽  
Peter G. Smith ◽  
Gail S. Eckhardt

The ubiquitin proteasome system (UPS) regulates the ubiquitination, and thus degradation and turnover, of many proteins vital to cellular regulation and function. The UPS comprises a sequential series of enzymatic processes using four key enzyme families: E1 (ubiquitin-activating enzymes), E2 (ubiquitin-carrier proteins), E3 (ubiquitin-protein ligases), and E4 (ubiquitin chain assembly factors). Because the UPS is a crucial regulator of the cell cycle, and abnormal cell-cycle control can lead to oncogenesis, aberrancies within the UPS pathway can result in a malignant cellular phenotype and thus has become an attractive target for novel anticancer agents. This article will provide an overall review of the mechanics of the UPS, describe aberrancies leading to cancer, and give an overview of current drug therapies selectively targeting the UPS.


Cells ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 2219 ◽  
Author(s):  
Tong Su ◽  
Mingyue Yang ◽  
Pingping Wang ◽  
Yanxiu Zhao ◽  
Changle Ma

All eukaryotes rely on the ubiquitin-proteasome system (UPS) and autophagy to control the abundance of key regulatory proteins and maintain a healthy intracellular environment. In the UPS, damaged or superfluous proteins are ubiquitinated and degraded in the proteasome, mediated by three types of ubiquitin enzymes: E1s (ubiquitin activating enzymes), E2s (ubiquitin conjugating enzymes), and E3s (ubiquitin protein ligases). Conversely, in autophagy, a vesicular autophagosome is formed that transfers damaged proteins and organelles to the vacuole, mediated by a series of ATGs (autophagy related genes). Despite the use of two completely different componential systems, the UPS and autophagy are closely interconnected and mutually regulated. During autophagy, ATG8 proteins, which are autophagosome markers, decorate the autophagosome membrane similarly to ubiquitination of damaged proteins. Ubiquitin is also involved in many selective autophagy processes and is thus a common factor of the UPS and autophagy. Additionally, the components of the UPS, such as the 26S proteasome, can be degraded via autophagy, and conversely, ATGs can be degraded by the UPS, indicating cross regulation between the two pathways. The UPS and autophagy cooperate and jointly regulate homeostasis of cellular components during plant development and stress response.


Cell Division ◽  
2012 ◽  
Vol 7 (1) ◽  
pp. 18 ◽  
Author(s):  
Panagiotis J Vlachostergios ◽  
Ioannis A Voutsadakis ◽  
Christos N Papandreou

2021 ◽  
Author(s):  
Lucie M. Wolf ◽  
Annika M. Lambert ◽  
Julie Haenlin ◽  
Michael Boutros

WNT signalling is important for development in all metazoan animals and is associated with various human diseases. The Ubiquitin-Proteasome System (UPS) and regulatory ER-associated degradation (ERAD) have been implicated in the production of WNT proteins. Here, we investigated how the WNT secretory factor EVI/WLS is ubiquitinated, recognised by ERAD components and subsequently removed from the secretory pathway. We performed a focused, immunoblot-based RNAi screen for factors that influence EVI/WLS protein stability. We identified the VCP-binding proteins FAF2 and UBXN4 as novel interaction partners of EVI/WLS and showed that ERLIN2 links EVI/WLS to the ubiquitination machinery. Interestingly, we found in addition that EVI/WLS is ubiquitinated and degraded in cells irrespective of their level of WNT production. This K11, K48, and K63-linked ubiquitination is mediated by the E2 ubiquitin conjugating enzymes UBE2J2, UBE2K, and UBE2N, but independent of the E3 ligases HRD1/SYVN or GP78/AMFR. Taken together, our study identified factors that link the UPS to the WNT secretory pathway and provides mechanistic details on the fate of an endogenous substrate of regulatory ERAD in mammalian cells.


2000 ◽  
Vol 113 (12) ◽  
pp. 2111-2117 ◽  
Author(s):  
R.A. Sclafani

Great insight into the molecular details of cell cycle regulation has been obtained in the past decade. However, most of the progress has been in defining the regulation of the family of cyclin-dependent kinases (CDKs). Recent studies of a myriad of eukaryotic organisms have defined both the regulation and substrates of Cdc7p kinase, which forms a CDK-cyclin-like complex with Dbf4p, is necessary for the initiation of DNA replication and has been conserved in evolution. This kinase is also required for the induction of mutations after DNA damage and for commitment to recombination in the meiotic cell cycle. However, less is known about the role of the kinase in these processes. In a manner similar to CDKs, Cdc7p is activated by a regulatory subunit, Dbf4, the levels of which fluctuate during the cell cycle. One or more subunits of the conserved MCM helicase complex at chromosomal origins of DNA replication are substrates for the kinase during S phase. Phosphorylation of the MCM complex by Cdc7p-Dbf4p might activate DNA replication by unwinding DNA. Therefore, activation of Cdc7p is required for DNA replication. Given that Cdc7p-Dbf4 kinase is overexpressed in many neoplastic cells and tumors, it might be an important early biomarker during cancer progression.


2020 ◽  
Vol 21 (6) ◽  
pp. 2008 ◽  
Author(s):  
Shuangqi Fan ◽  
Keke Wu ◽  
Mengpo Zhao ◽  
Erpeng Zhu ◽  
Shengming Ma ◽  
...  

Autophagy is a general protective mechanism for maintaining homeostasis in eukaryotic cells, regulating cellular metabolism, and promoting cell survival by degrading and recycling cellular components under stress conditions. The degradation pathway that is mediated by autophagy receptors is called selective autophagy, also named as xenophagy. Autophagy receptor NDP52 acts as a ‘bridge’ between autophagy and the ubiquitin-proteasome system, and it also plays an important role in the process of selective autophagy. Pathogenic microbial infections cause various diseases in both humans and animals, posing a great threat to public health. Increasing evidence has revealed that autophagy and autophagy receptors are involved in the life cycle of pathogenic microbial infections. The interaction between autophagy receptor and pathogenic microorganism not only affects the replication of these microorganisms in the host cell, but it also affects the host’s immune system. This review aims to discuss the effects of autophagy on pathogenic microbial infection and replication, and summarizes the mechanisms by which autophagy receptors interact with microorganisms. While considering the role of autophagy receptors in microbial infection, NDP52 might be a potential target for developing effective therapies to treat pathogenic microbial infections.


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