scholarly journals Targeting Post-Translational Modifications of the p73 Protein: A Promising Therapeutic Strategy for Tumors

Cancers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1916
Author(s):  
Ziad Omran ◽  
Mahmood H. Dalhat ◽  
Omeima Abdullah ◽  
Mohammed Kaleem ◽  
Salman Hosawi ◽  
...  

The tumor suppressor p73 is a member of the p53 family and is expressed as different isoforms with opposing properties. The TAp73 isoforms act as tumor suppressors and have pro-apoptotic effects, whereas the ΔNp73 isoforms lack the N-terminus transactivation domain and behave as oncogenes. The TAp73 protein has a high degree of similarity with both p53 function and structure, and it induces the regulation of various genes involved in the cell cycle and apoptosis. Unlike those of the p53 gene, the mutations in the p73 gene are very rare in tumors. Cancer cells have developed several mechanisms to inhibit the activity and/or expression of p73, from the hypermethylation of its promoter to the modulation of the ratio between its pro- and anti-apoptotic isoforms. The p73 protein is also decorated by a panel of post-translational modifications, including phosphorylation, acetylation, ubiquitin proteasomal pathway modifications, and small ubiquitin-related modifier (SUMO)ylation, that regulate its transcriptional activity, subcellular localization, and stability. These modifications orchestrate the multiple anti-proliferative and pro-apoptotic functions of TAp73, thereby offering multiple promising candidates for targeted anti-cancer therapies. In this review, we summarize the current knowledge of the different pathways implicated in the regulation of TAp73 at the post-translational level. This review also highlights the growing importance of targeting the post-translational modifications of TAp73 as a promising antitumor strategy, regardless of p53 status.

Plants ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1788
Author(s):  
Moumita Srivastava ◽  
Ari Sadanandom

Due to their sessile nature, plants are constantly subjected to various environmental stresses such as drought, salinity, and pathogen infections. Post-translational modifications (PTMs), like SUMOylation, play a vital role in the regulation of plant responses to their environment. The process of SUMOylation typically involves an enzymatic cascade containing the activation, (E1), conjugation (E2), and ligation (E3) of SUMO to a target protein. Additionally, it also requires a class of SUMO proteases that generate mature SUMO from its precursor and cleave it off the target protein, a process termed deSUMOylation. It is now clear that SUMOylation in plants is key to a plethora of adaptive responses. How this is achieved with an extremely limited set of machinery components is still unclear. One possibility is that novel SUMO components are yet to be discovered. However, current knowledge indicates that only a small set of enzymes seem to be responsible for the modification of a large number of SUMO substrates. It is yet unknown where the specificity lies within the SUMO system. Although this seems to be a crucial question in the field of SUMOylation studies, not much is known about the factors that provide specificity. In this review, we highlight the role of the localisation of SUMO components as an important factor that can play a vital role in contributing to the specificity within the process. This will introduce a new facet to our understanding of the mechanisms underlying such a dynamic process.


2020 ◽  
Vol 21 ◽  
Author(s):  
Sonali Mehendale-Munj

: Breast Cancer Resistance Protein (BCRP) is an efflux transporter responsible for causing multidrug re-sistance(MDR). It is known to expel many potent antineoplastic drugs, owing to its efflux function. Efflux of chemothera-peutics because of BCRP develops resistance to manydrugs, leading to failure in cancer treatment. BCRP plays an important role in physiology by protecting the organism from xenobiotics and other toxins. It is a half-transporter affiliated to theATP-binding cassette (ABC) superfamily of transporters, encoded by the gene ABCG2 and functions in response to adenosine triphosphate (ATP). Regulation of BCRP expression is critically controlled at molecular levels which help in maintaining the balance of xenobiotics and nutrients inside the body. Expression of BCRP can be found in brain, liver, lung cancers and acute myeloid leukemia (AML). Moreover, it is also expressed at high levels in stem cells and many cell lines. This frequent expression of BCRP has an impact on the treatment procedures and if not scrutinized may lead to failure of many cancer therapies.


2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Yanan Shi ◽  
Jingjing Zhu ◽  
Yan Xu ◽  
Xiaozhao Tang ◽  
Zushun Yang ◽  
...  

Abstract Background Protein lysine malonylation, a novel post-translational modification (PTM), has been recently linked with energy metabolism in bacteria. Staphylococcus aureus is the third most important foodborne pathogen worldwide. Nonetheless, substrates and biological roles of malonylation are still poorly understood in this pathogen. Results Using anti-malonyl-lysine antibody enrichment and high-resolution LC-MS/MS analysis, 440 lysine-malonylated sites were identified in 281 proteins of S. aureus strain. The frequency of valine in position − 1 and alanine at + 2 and + 4 positions was high. KEGG pathway analysis showed that six categories were highly enriched, including ribosome, glycolysis/gluconeogenesis, pentose phosphate pathway (PPP), tricarboxylic acid cycle (TCA), valine, leucine, isoleucine degradation, and aminoacyl-tRNA biosynthesis. In total, 31 malonylated sites in S. aureus shared homology with lysine-malonylated sites previously identified in E. coli, indicating malonylated proteins are highly conserved among bacteria. Key rate-limiting enzymes in central carbon metabolic pathways were also found to be malonylated in S. aureus, namely pyruvate kinase (PYK), 6-phosphofructokinase, phosphoglycerate kinase, dihydrolipoyl dehydrogenase, and F1F0-ATP synthase. Notably, malonylation sites were found at or near protein active sites, including KH domain protein, thioredoxin, alanine dehydrogenase (ALD), dihydrolipoyl dehydrogenase (LpdA), pyruvate oxidase CidC, and catabolite control protein A (CcpA), thus suggesting that lysine malonylation may affect the activity of such enzymes. Conclusions Data presented herein expand the current knowledge on lysine malonylation in prokaryotes and indicate the potential roles of protein malonylation in bacterial physiology and metabolism.


Biomolecules ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 129
Author(s):  
Hae Ryung Chang ◽  
Eunyoung Jung ◽  
Soobin Cho ◽  
Young-Jun Jeon ◽  
Yonghwan Kim

While Next-Generation Sequencing (NGS) and technological advances have been useful in identifying genetic profiles of tumorigenesis, novel target proteins and various clinical biomarkers, cancer continues to be a major global health threat. DNA replication, DNA damage response (DDR) and repair, and cell cycle regulation continue to be essential systems in targeted cancer therapies. Although many genes involved in DDR are known to be tumor suppressor genes, cancer cells are often dependent and addicted to these genes, making them excellent therapeutic targets. In this review, genes implicated in DNA replication, DDR, DNA repair, cell cycle regulation are discussed with reference to peptide or small molecule inhibitors which may prove therapeutic in cancer patients. Additionally, the potential of utilizing novel synthetic lethal genes in these pathways is examined, providing possible new targets for future therapeutics. Specifically, we evaluate the potential of TONSL as a novel gene for targeted therapy. Although it is a scaffold protein with no known enzymatic activity, the strategy used for developing PCNA inhibitors can also be utilized to target TONSL. This review summarizes current knowledge on non-oncogene addiction, and the utilization of synthetic lethality for developing novel inhibitors targeting non-oncogenic addiction for cancer therapy.


2000 ◽  
Vol 18 (7) ◽  
pp. 1465-1473 ◽  
Author(s):  
Arnauld Cabelguenne ◽  
Hélène Blons ◽  
Isabelle de Waziers ◽  
Françoise Carnot ◽  
Anne-Marie Houllier ◽  
...  

PURPOSE: The tumor suppressor gene p53 plays a crucial role in cell cycle control and apoptosis in response to DNA damages. p53 gene mutations and allelic losses at 17p are one of the most common genetic alterations in primary head and neck squamous cell carcinoma (HNSCC). Alterations of the p53 gene have been shown to contribute to carcinogenesis and drug resistance. PATIENTS AND METHODS: In this prospective series, patients with HNSCC were treated with cisplatin-fluorouracil neoadjuvant chemotherapy. p53 status was characterized in 106 patients with HNSCC (p53 mutations, allelic losses at p53 locus, and plasma anti-p53 antibodies) to determine the existence of a relationship between p53 gene status and response to neoadjuvant chemotherapy. RESULTS: Exons 4 to 9 of the p53 gene were analyzed, and mutations were found in 72 of 106 patients with HNSCC. p53 mutations were associated with loss of heterozygosity at chromosome 17p (P < .001). The prevalence of p53-mutated tumors was higher in the group of patients with nonresponse to neoadjuvant chemotherapy than in the group of responders (81% v 61%, respectively; P < .04). When compiling p53 mutations and anti-p53 antibodies in plasma, the correlation between p53 status and response to chemotherapy was significant (87% v 57%, respectively; P = .003). A multivariate analysis showed that p53 status is an independent predictive factor of response to chemotherapy. CONCLUSION: This prospective study suggests that p53 status may be a useful indicator of response to neoadjuvant chemotherapy in HNSCC.


PPAR Research ◽  
2012 ◽  
Vol 2012 ◽  
pp. 1-16 ◽  
Author(s):  
Marion Peyrou ◽  
Pierluigi Ramadori ◽  
Lucie Bourgoin ◽  
Michelangelo Foti

Peroxisome-proliferator-activated receptors (PPARs) are ligand-activated nuclear receptors that exert in the liver a transcriptional activity regulating a whole spectrum of physiological functions, including cholesterol and bile acid homeostasis, lipid/glucose metabolism, inflammatory responses, regenerative mechanisms, and cell differentiation/proliferation. Dysregulations of the expression, or activity, of specific PPAR isoforms in the liver are therefore believed to represent critical mechanisms contributing to the development of hepatic metabolic diseases, disorders induced by hepatic viral infections, and hepatocellular adenoma and carcinoma. In this regard, specific PPAR agonists have proven to be useful to treat these metabolic diseases, but for cancer therapies, the use of PPAR agonists is still debated. Interestingly, in addition to previously described mechanisms regulating PPARs expression and activity, microRNAs are emerging as new important regulators of PPAR expression and activity in pathophysiological conditions and therefore may represent future therapeutic targets to treat hepatic metabolic disorders and cancers. Here, we reviewed the current knowledge about the general roles of the different PPAR isoforms in common chronic metabolic and infectious liver diseases, as well as in the development of hepatic cancers. Recent works highlighting the regulation of PPARs by microRNAs in both physiological and pathological situations with a focus on the liver are also discussed.


2004 ◽  
Vol 11 (8) ◽  
pp. 547-554 ◽  
Author(s):  
Sven R Quist ◽  
Shan Wang-Gohrke ◽  
Tanja Köhler ◽  
Rolf Kreienberg ◽  
Ingo B Runnebaum

2001 ◽  
Vol 21 (15) ◽  
pp. 5109-5121 ◽  
Author(s):  
Yann-Gaël Gangloff ◽  
Jean-Christophe Pointud ◽  
Sylvie Thuault ◽  
Lucie Carré ◽  
Christophe Romier ◽  
...  

ABSTRACT The RNA polymerase II transcription factor TFIID comprises the TATA binding protein (TBP) and a set of TBP-associated factors (TAFIIs). TFIID has been extensively characterized for yeast, Drosophila, and humans, demonstrating a high degree of conservation of both the amino acid sequences of the constituent TAFIIs and overall molecular organization. In recent years, it has been assumed that all the metazoan TAFIIs have been identified, yet no metazoan homologues of yeast TAFII47 (yTAFII47) and yTAFII65 are known. Both of these yTAFIIs contain a histone fold domain (HFD) which selectively heterodimerizes with that of yTAFII25. We have cloned a novel mouse protein, TAFII140, containing an HFD and a plant homeodomain (PHD) finger, which we demonstrated by immunoprecipitation to be a mammalian TFIID component. TAFII140 shows extensive sequence similarity toDrosophila BIP2 (dBIP2) (dTAFII155), which we also show to be a component of DrosophilaTFIID. These proteins are metazoan homologues of yTAFII47 as their HFDs selectively heterodimerize with dTAFII24 and human TAFII30, metazoan homologues of yTAFII25. We further show that yTAFII65 shares two domains with theDrosophila Prodos protein, a recently described potential dTAFII. These conserved domains are critical for yTAFII65 function in vivo. Our results therefore identify metazoan homologues of yTAFII47 and yTAFII65.


eLife ◽  
2022 ◽  
Vol 11 ◽  
Author(s):  
Ananya Chakravarti ◽  
Heshani N Thirimanne ◽  
Savanna Brown ◽  
Brian R Calvi

p53 gene family members in humans and other organisms encode a large number of protein isoforms whose functions are largely undefined. Using Drosophila as a model, we find that a p53B isoform is expressed predominantly in the germline where it colocalizes with p53A into subnuclear bodies. It is only p53A, however, that mediates the apoptotic response to ionizing radiation in the germline and soma. In contrast, p53A and p53B are both required for the normal repair of meiotic DNA breaks, an activity that is more crucial when meiotic recombination is defective. We find that in oocytes with persistent DNA breaks p53A is also required to activate a meiotic pachytene checkpoint. Our findings indicate that Drosophila p53 isoforms have DNA lesion and cell type-specific functions, with parallels to the functions of mammalian p53 family members in the genotoxic stress response and oocyte quality control.


2021 ◽  
Vol 10 ◽  
Author(s):  
Yifan Ma ◽  
Shiyan Dong ◽  
Xuefeng Li ◽  
Betty Y. S. Kim ◽  
Zhaogang Yang ◽  
...  

Extracellular vesicles (EVs) are cell-derived membrane particles that represent an endogenous mechanism for cell-to-cell communication. Since discovering that EVs have multiple advantages over currently available delivery platforms, such as their ability to overcome natural barriers, intrinsic cell targeting properties, and circulation stability, the potential use of EVs as therapeutic nanoplatforms for cancer studies has attracted considerable interest. To fully elucidate EVs’ therapeutic function for treating cancer, all current knowledge about cellular uptake and trafficking of EVs will be initially reviewed. In order to further improve EVs as anticancer therapeutics, engineering strategies for cancer therapy have been widely explored in the last decade, along with other cancer therapies. However, therapeutic applications of EVs as drug delivery systems have been limited because of immunological concerns, lack of methods to scale EV production, and efficient drug loading. We will review and discuss recent progress and remaining challenges in developing EVs as a delivery nanoplatform for cancer therapy.


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