scholarly journals Wrestling and Wrapping: A Perspective on SUMO Proteins in Schwann Cells

Biomolecules ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1055
Author(s):  
Iman F. Fergani ◽  
Luciana R. Frick
Keyword(s):  
Schwann Cells ◽  
Posttranslational Modifications ◽  
Cellular Localization ◽  
Covalent Attachment ◽  
Protein Protein Interaction ◽  
Cellular Processes ◽  
Schwann Cell Development ◽  
Demyelinating Neuropathies ◽  
Underlying Mechanisms ◽  
Substrate Proteins

Schwann cell development and peripheral nerve myelination are finely orchestrated multistep processes; some of the underlying mechanisms are well described and others remain unknown. Many posttranslational modifications (PTMs) like phosphorylation and ubiquitination have been reported to play a role during the normal development of the peripheral nervous system (PNS) and in demyelinating neuropathies. However, a relatively novel PTM, SUMOylation, has not been studied in these contexts. SUMOylation involves the covalent attachment of one or more small ubiquitin-like modifier (SUMO) proteins to a substrate, which affects the function, cellular localization, and further PTMs of the conjugated protein. SUMOylation also regulates other proteins indirectly by facilitating non-covalent protein–protein interaction via SUMO interaction motifs (SIM). This pathway has important consequences on diverse cellular processes, and dysregulation of this pathway has been reported in several diseases including neurological and degenerative conditions. In this article, we revise the scarce literature on SUMOylation in Schwann cells and the PNS, we propose putative substrate proteins, and we speculate on potential mechanisms underlying the possible involvement of this PTM in peripheral myelination and neuropathies.

Dynamics of Protein-Protein Interaction Network in Plasmodium Falciparum

2009 ◽  
pp. 257-284
Author(s):  
Smita Mohanty ◽  
Shashi Bhushan Pandit ◽  
Narayanaswamy Srinivasan
Keyword(s):  
Plasmodium Falciparum ◽  
Protein Interaction ◽  
Protein Interaction Network ◽  
Cellular Localization ◽  
Interaction Network ◽  
Malarial Parasite ◽  
Strategic Integration ◽  
Protein Protein Interaction ◽  
Cellular Processes ◽  
Expression Of Genes

Integration of organism-wide protein interactome data with information on expression of genes, cellular localization of proteins and their functions has proved extremely useful in developing biologically intuitive interaction networks. This chapter highlights the dynamics in protein interaction network across different stages in the lifecycle of Plasmodium falciparum, a malarial parasite, and the implication of the network dynamics in different physiological processes. The main focus of the chapter is the integration of information on experimentally derived interactions of P.falciparum proteins with expression data and analysis of the implications of interactions in different cellular processes. Extensive analysis has been made to quantify the interaction dynamics across various stages, as well as correlating it with the dynamics of the cellular pathways involving the interacting proteins. The authors’ analysis demonstrates the power of strategic integration of genome-wide datasets in extracting information on dynamics of biological pathways and processes.

scholarly journals Post-translational regulation of ubiquitin signaling

2019 ◽  
Vol 218 (6) ◽  
pp. 1776-1786 ◽  
Author(s):  
Lei Song ◽  
Zhao-Qing Luo
Keyword(s):  
Translational Regulation ◽  
Covalent Attachment ◽  
Immune Disorders ◽  
Post Translational Modification ◽  
Polyubiquitin Chains ◽  
Cellular Processes ◽  
Lysine Residues ◽  
Substrate Proteins ◽  
Ubiquitination Machinery ◽  
Integrate Development

Ubiquitination regulates many essential cellular processes in eukaryotes. This post-translational modification (PTM) is typically achieved by E1, E2, and E3 enzymes that sequentially catalyze activation, conjugation, and ligation reactions, respectively, leading to covalent attachment of ubiquitin, usually to lysine residues of substrate proteins. Ubiquitin can also be successively linked to one of the seven lysine residues on ubiquitin to form distinctive forms of polyubiquitin chains, which, depending upon the lysine used and the length of the chains, dictate the fate of substrate proteins. Recent discoveries revealed that this ubiquitin code is further expanded by PTMs such as phosphorylation, acetylation, deamidation, and ADP-ribosylation, on ubiquitin, components of the ubiquitination machinery, or both. These PTMs provide additional regulatory nodes to integrate development or insulting signals with cellular homeostasis. Understanding the precise roles of these PTMs in the regulation of ubiquitin signaling will provide new insights into the mechanisms and treatment of various human diseases linked to ubiquitination, including neurodegenerative diseases, cancer, infection, and immune disorders.

scholarly journals Mechanisms, regulation and consequences of protein SUMOylation

2010 ◽  
Vol 428 (2) ◽  
pp. 133-145 ◽  
Author(s):  
Kevin A. Wilkinson ◽  
Jeremy M. Henley
Keyword(s):  
Protein Function ◽  
Covalent Attachment ◽  
Post Translational Modification ◽  
Cellular Processes ◽  
Wide Range ◽  
Lysine Residues ◽  
Ubiquitination Pathway ◽  
Regulate Protein ◽  
Substrate Proteins ◽  
Protein Sumoylation

The post-translational modification SUMOylation is a major regulator of protein function that plays an important role in a wide range of cellular processes. SUMOylation involves the covalent attachment of a member of the SUMO (small ubiquitin-like modifier) family of proteins to lysine residues in specific target proteins via an enzymatic cascade analogous to, but distinct from, the ubiquitination pathway. There are four SUMO paralogues and an increasing number of proteins are being identified as SUMO substrates. However, in many cases little is known about how SUMOylation of these targets is regulated. Compared with the ubiquitination pathway, relatively few components of the conjugation machinery have been described and the processes that specify individual SUMO paralogue conjugation to defined substrate proteins are an active area of research. In the present review, we briefly describe the SUMOylation pathway and present an overview of the recent findings that are beginning to identify some of the mechanisms that regulate protein SUMOylation.

scholarly journals Emerging roles of the HECT-type E3 ubiquitin ligases in hematological malignancies

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Vincenza Simona Delvecchio ◽  
Claudia Fierro ◽  
Sara Giovannini ◽  
Gerry Melino ◽  
Francesca Bernassola
Keyword(s):  
Hematological Malignancies ◽  
Apoptotic Cell ◽  
Ubiquitin Ligases ◽  
Covalent Attachment ◽  
E3 Ubiquitin Ligases ◽  
Comprehensive Overview ◽  
Altered Expression ◽  
Hect Domain ◽  
Cellular Processes ◽  
Substrate Proteins

AbstractUbiquitination-mediated proteolysis or regulation of proteins, ultimately executed by E3 ubiquitin ligases, control a wide array of cellular processes, including transcription, cell cycle, autophagy and apoptotic cell death. HECT-type E3 ubiquitin ligases can be distinguished from other subfamilies of E3 ubiquitin ligases because they have a C-terminal HECT domain that directly catalyzes the covalent attachment of ubiquitin to their substrate proteins. Deregulation of HECT-type E3-mediated ubiquitination plays a prominent role in cancer development and chemoresistance. Several members of this subfamily are indeed frequently deregulated in human cancers as a result of genetic mutations and altered expression or activity. HECT-type E3s contribute to tumorigenesis by regulating the ubiquitination rate of substrates that function as either tumour suppressors or oncogenes. While the pathological roles of the HECT family members in solid tumors are quite well established, their contribution to the pathogenesis of hematological malignancies has only recently emerged. This review aims to provide a comprehensive overview of the involvement of the HECT-type E3s in leukemogenesis.

SUMO and ubiquitin paths converge

2010 ◽  
Vol 38 (1) ◽  
pp. 34-39 ◽  
Author(s):  
Amanda Denuc ◽  
Gemma Marfany
Keyword(s):  
Genome Stability ◽  
Cell Signalling ◽  
Covalent Attachment ◽  
Small Peptides ◽  
Protein Activity ◽  
Protein Protein Interaction ◽  
Cellular Processes ◽  
Reversible Covalent ◽  
And Function

One of the more rapidly expanding fields in cell signalling nowadays is the characterization of proteins conjugated to Ub (ubiquitin) or Ub-like peptides, such as SUMO (small Ub-related modifier). The reversible covalent attachment of these small peptides remodels the target protein, providing new protein–protein interaction interfaces, which can be dynamically regulated given a set of enzymes for conjugation and deconjugation. First, ubiquitination was thought to be merely relegated to the control of protein turnover and degradation, whereas the attachment of SUMO was involved in the regulation of protein activity and function. However, the boundaries between the protein fates related to these tag molecules are becoming more and more fuzzy, as either the differences between mono-, multi- and poly-modifications or the lysine residue used for growth of the poly-chains is being dissected. The Ub and SUMO pathways are no longer separated, and many examples of this cross-talk are found in the literature, involving different cellular processes ranging from DNA repair and genome stability, to the regulation of protein subcellular localization or enzyme activity. Here, we review several cases in which SUMOylation and ubiquitination intersect, showing also that the same protein can be conjugated to SUMO and Ub for antagonistic, synergistic or multiple outcomes, illustrating the intricacy of the cellular signalling networks. Ub and SUMO have met and are now applying for new regulatory roles in the cell.

Metabolism of Oxalate in Humans: A Potential Role Kynurenine Aminotransferase/Glutamine Transaminase/Cysteine Conjugate Betalyase Plays in Hyperoxaluria

2019 ◽  
Vol 26 (26) ◽  
pp. 4944-4963 ◽  
Author(s):  
Qian Han ◽  
Cihan Yang ◽  
Jun Lu ◽  
Yinai Zhang ◽  
Jianyong Li
Keyword(s):  
Cellular Localization ◽  
Structural Characteristics ◽  
Gene Mutations ◽  
Primary Hyperoxaluria ◽  
Glycolate Oxidase ◽  
Kynurenine Aminotransferase ◽  
Underlying Mechanisms ◽  
Urinary Oxalate Excretion ◽  
Glyoxylate Aminotransferase ◽  
Oxalate Metabolism

Hyperoxaluria, excessive urinary oxalate excretion, is a significant health problem worldwide. Disrupted oxalate metabolism has been implicated in hyperoxaluria and accordingly, an enzymatic disturbance in oxalate biosynthesis can result in the primary hyperoxaluria. Alanine-glyoxylate aminotransferase-1 and glyoxylate reductase, the enzymes involving glyoxylate (precursor for oxalate) metabolism, have been related to primary hyperoxalurias. Some studies suggest that other enzymes such as glycolate oxidase and alanine-glyoxylate aminotransferase-2 might be associated with primary hyperoxaluria as well, but evidence of a definitive link is not strong between the clinical cases and gene mutations. There are still some idiopathic hyperoxalurias, which require a further study for the etiologies. Some aminotransferases, particularly kynurenine aminotransferases, can convert glyoxylate to glycine. Based on biochemical and structural characteristics, expression level, and subcellular localization of some aminotransferases, a number of them appear able to catalyze the transamination of glyoxylate to glycine more efficiently than alanine glyoxylate aminotransferase-1. The aim of this minireview is to explore other undermining causes of primary hyperoxaluria and stimulate research toward achieving a comprehensive understanding of underlying mechanisms leading to the disease. Herein, we reviewed all aminotransferases in the liver for their functions in glyoxylate metabolism. Particularly, kynurenine aminotransferase-I and III were carefully discussed regarding their biochemical and structural characteristics, cellular localization, and enzyme inhibition. Kynurenine aminotransferase-III is, so far, the most efficient putative mitochondrial enzyme to transaminate glyoxylate to glycine in mammalian livers, which might be an interesting enzyme to look for in hyperoxaluria etiology of primary hyperoxaluria and should be carefully investigated for its involvement in oxalate metabolism.

scholarly journals A Concerted Action of UBA5 C-Terminal Unstructured Regions Is Important for Transfer of Activated UFM1 to UFC1

2021 ◽  
Vol 22 (14) ◽  
pp. 7390
Author(s):  
Nicole Wesch ◽  
Frank Löhr ◽  
Natalia Rogova ◽  
Volker Dötsch ◽  
Vladimir V. Rogov
Keyword(s):  
Cellular Localization ◽  
Molecular Mechanisms ◽  
Biochemical Characterization ◽  
Effective Interaction ◽  
Regulatory Region ◽  
Titration Calorimetry ◽  
Enzymatic Reactions ◽  
Cellular Processes ◽  
Mechanism Of Interaction

Ubiquitin fold modifier 1 (UFM1) is a member of the ubiquitin-like protein family. UFM1 undergoes a cascade of enzymatic reactions including activation by UBA5 (E1), transfer to UFC1 (E2) and selective conjugation to a number of target proteins via UFL1 (E3) enzymes. Despite the importance of ufmylation in a variety of cellular processes and its role in the pathogenicity of many human diseases, the molecular mechanisms of the ufmylation cascade remains unclear. In this study we focused on the biophysical and biochemical characterization of the interaction between UBA5 and UFC1. We explored the hypothesis that the unstructured C-terminal region of UBA5 serves as a regulatory region, controlling cellular localization of the elements of the ufmylation cascade and effective interaction between them. We found that the last 20 residues in UBA5 are pivotal for binding to UFC1 and can accelerate the transfer of UFM1 to UFC1. We solved the structure of a complex of UFC1 and a peptide spanning the last 20 residues of UBA5 by NMR spectroscopy. This structure in combination with additional NMR titration and isothermal titration calorimetry experiments revealed the mechanism of interaction and confirmed the importance of the C-terminal unstructured region in UBA5 for the ufmylation cascade.

scholarly journals The AAA+ ATPase p97, a cellular multitool

2017 ◽  
Vol 474 (17) ◽  
pp. 2953-2976 ◽  
Author(s):  
Lasse Stach ◽  
Paul S. Freemont
Keyword(s):  
Atp Hydrolysis ◽  
Current Status ◽  
Cellular Functions ◽  
Aaa Atpase ◽  
Cellular Processes ◽  
Proteotoxic Stress ◽  
Binding Domains ◽  
Wide Range ◽  
Aaa Atpases ◽  
Substrate Proteins

The AAA+ (ATPases associated with diverse cellular activities) ATPase p97 is essential to a wide range of cellular functions, including endoplasmic reticulum-associated degradation, membrane fusion, NF-κB (nuclear factor kappa-light-chain-enhancer of activated B cells) activation and chromatin-associated processes, which are regulated by ubiquitination. p97 acts downstream from ubiquitin signaling events and utilizes the energy from ATP hydrolysis to extract its substrate proteins from cellular structures or multiprotein complexes. A multitude of p97 cofactors have evolved which are essential to p97 function. Ubiquitin-interacting domains and p97-binding domains combine to form bi-functional cofactors, whose complexes with p97 enable the enzyme to interact with a wide range of ubiquitinated substrates. A set of mutations in p97 have been shown to cause the multisystem proteinopathy inclusion body myopathy associated with Paget's disease of bone and frontotemporal dementia. In addition, p97 inhibition has been identified as a promising approach to provoke proteotoxic stress in tumors. In this review, we will describe the cellular processes governed by p97, how the cofactors interact with both p97 and its ubiquitinated substrates, p97 enzymology and the current status in developing p97 inhibitors for cancer therapy.

scholarly journals MiRNA-143 mediates the proliferative signaling pathway of FSH and regulates estradiol production

2017 ◽  
Vol 234 (1) ◽  
pp. 1-14 ◽  
Author(s):  
Li Zhang ◽  
XiaoXin Zhang ◽  
Xuejing Zhang ◽  
Yu Lu ◽  
Lei Li ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Granulosa Cell ◽  
Granulosa Cells ◽  
Loss Of Function ◽  
Cellular Processes ◽  
Cell Functions ◽  
Genes Expression ◽  
Underlying Mechanisms

MicroRNAs (MiRNAs) play important regulatory roles in many cellular processes. MiR-143 is highly enriched in the mouse ovary, but its roles and underlying mechanisms are not well understood. In the current study, we show that miR-143 is located in granulosa cells of primary, secondary and antral follicles. To explore the specific functions of miR-143, we transfected miR-143 inhibitor into primary cultured granulosa cells to study the loss of function of miR-143 and the results showed that miR-143 silencing significantly increased estradiol production and steroidogenesis-related gene expression. Moreover, our in vivo and in vitro studies showed that follicular stimulating hormone (FSH) significantly decreased miR-143 expression. This function of miR-143 is accomplished by its binding to the 3’-UTR of KRAS mRNA. Furthermore, our results demonstrated that miR-143 acts as a negative regulating molecule mediating the signaling pathway of FSH and affecting estradiol production by targeting KRAS. MiR-143 also negatively acts in regulating granulosa cells proliferation and cell cycle-related genes expression. These findings indicate that miR-143 plays vital roles in FSH-induced estradiol production and granulosa cell proliferation, providing a novel mechanism that involves miRNA in regulating granulosa cell functions.

scholarly journals Lipocalin 2 as Putative Modulator of Local Inflammatory Processes in the Spinal Cord and Component of Organ Cross-talk After Spinal Cord Injury

2021 ◽  
Author(s):  
Victoria Behrens ◽  
Clara Voelz ◽  
Nina Müller ◽  
Weiyi Zhao ◽  
Tim Clarner ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Blood Serum ◽  
Negative Influence ◽  
Lipocalin 2 ◽  
Cellular Processes ◽  
Cord Injury ◽  
Inflammatory Processes ◽  
Underlying Mechanisms ◽  
Sites Of Action

Abstract Lipocalin 2 (Lcn2), an immunomodulator, regulates various cellular processes such as iron transport and defense against bacterial infection. Under pathological conditions, Lcn2 promotes neuroinflammation via the recruitment and activation of immune cells and glia, particularly microglia and astrocytes. Although it seems to have a negative influence on the functional outcome in spinal cord injury (SCI), the extent of its involvement in SCI and the underlying mechanisms are not yet fully known. In this study, using a SCI contusion mouse model, we first investigated the expression pattern of Lcn2 in different parts of the CNS (spinal cord and brain), blood serum and in the liver. Interestingly, we could note a significant increase in Lcn2 throughout the whole spinal cord, in the brain, liver and in blood serum. This demonstrates the diversity of its possible sites of action in SCI. Further, genetic deficiency of Lcn2 (Lcn2-/-) significantly reduced certain aspects of gliosis in the SCI-mice. Taken together, our studies provide first valuable hints, suggesting that Lcn2 is involved in the local and systemic effects post SCI, and might modulate the impairment of different peripheral organs after injury.

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