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Current Biology : CB May 2021Actin is one of the most abundant proteins in eukaryotes. Discovered in muscle and described as far back as 1887, actin was first purified in 1942. It plays myriad roles...
Actin is one of the most abundant proteins in eukaryotes. Discovered in muscle and described as far back as 1887, actin was first purified in 1942. It plays myriad roles in essentially every eukaryotic cell. Actin is central to development, muscle contraction, and cell motility, and it also functions in the nucleus, to name a spectrum of examples. The flexibility of actin function stems from two factors: firstly, it is dynamic, transitioning between monomer and filament, and, secondly, there are hundreds of actin-binding proteins that build and organize specific actin-based structures. Of prime importance are actin nucleators - proteins that stimulate de novo formation of actin filaments. There are three known classes of actin nucleators: the Arp2/3 complex, formins, and tandem WASP homology 2 (WH2) nucleators. Each class nucleates by a distinct mechanism that contributes to the organization of the larger structure being built. Evidence shows that the Arp2/3 complex produces branched actin filaments, remaining bound at the branch point, while formins create linear actin filaments, remaining bound at the growing end. Here, we focus on the formin family of actin nucleators.
Topics: Actin Cytoskeleton; Actin-Related Protein 2-3 Complex; Actins; Formins; Microfilament Proteins
PubMed: 34033783
DOI: 10.1016/j.cub.2021.02.047 -
Discovery Medicine 2021Actin-binding protein (transgelin, TAGLN) is a kind of protein that regulates actin polymerization, aggregating (or bundling), or cross-linking. As a member of the... (Review)
Review
Actin-binding protein (transgelin, TAGLN) is a kind of protein that regulates actin polymerization, aggregating (or bundling), or cross-linking. As a member of the actin-binding protein complex, transgelin-2 is involved in the regulation of cytoskeleton. Transgelin-2 is widely expressed in various tissues and organs of the body, but its abnormal expression is often seen in all kinds of tumors, which is related to the occurrence and development, and especially the invasion, metastasis, and drug resistance in many kinds of malignant tumors. However, the signal pathway involved in the regulation of transgelin-2 and its mechanism have remained to be elucidated. In recent years, with a more in-depth study of transgelin-2, its relationship with tumorigenesis has become increasingly clear. Therefore, we review recent research progress in transgelin-2, which is helpful to provide ideas for further research and bring forth a new scheme for the diagnosis, treatment, and prognosis of tumors.
Topics: Carcinogenesis; Humans; Microfilament Proteins; Muscle Proteins; Neoplasms
PubMed: 35219353
DOI: No ID Found -
Current Biology : CB May 2018Alto and Terman introduce the MICAL family of actin regulatory redox enzymes. (Review)
Review
Alto and Terman introduce the MICAL family of actin regulatory redox enzymes.
Topics: Actins; Adaptor Proteins, Signal Transducing; Animals; Cytoskeletal Proteins; DNA-Binding Proteins; Humans; LIM Domain Proteins; Microfilament Proteins; Mixed Function Oxygenases; Oxidation-Reduction; Oxidoreductases
PubMed: 29738722
DOI: 10.1016/j.cub.2018.01.025 -
Cells Oct 2020The actin cytoskeleton plays a crucial role in many cellular processes while its reorganization is important in maintaining cell homeostasis. However, in the case of... (Review)
Review
The actin cytoskeleton plays a crucial role in many cellular processes while its reorganization is important in maintaining cell homeostasis. However, in the case of cancer cells, actin and ABPs (actin-binding proteins) are involved in all stages of carcinogenesis. Literature has reported that ABPs such as SATB1 (special AT-rich binding protein 1), WASP (Wiskott-Aldrich syndrome protein), nesprin, and villin take part in the initial step of carcinogenesis by regulating oncogene expression. Additionally, changes in actin localization promote cell proliferation by inhibiting apoptosis (SATB1). In turn, migration and invasion of cancer cells are based on the formation of actin-rich protrusions (Arp2/3 complex, filamin A, fascin, α-actinin, and cofilin). Importantly, more and more scientists suggest that microfilaments together with the associated proteins mediate tumor vascularization. Hence, the presented article aims to summarize literature reports in the context of the potential role of actin and ABPs in all steps of carcinogenesis.
Topics: Actins; Carcinogenesis; Cell Movement; Humans; Microfilament Proteins
PubMed: 33036298
DOI: 10.3390/cells9102245 -
Science Advances Aug 2023In osteoarthritis (OA), a disease characterized by progressive articular cartilage degradation and calcification, the articular chondrocyte phenotype changes and this...
In osteoarthritis (OA), a disease characterized by progressive articular cartilage degradation and calcification, the articular chondrocyte phenotype changes and this correlates with actin cytoskeleton alterations suggesting that it regulates gene expression essential for proper phenotype. This study reports that OA is associated with the loss of adseverin, an actin capping and severing protein. Adseverin deletion (Adseverin) in mice compromised articular chondrocyte function, by reducing F-actin and aggrecan expression and increasing apoptosis, Indian hedgehog, Runx2, MMP13, and collagen type X expression, and cell proliferation. This led to stiffer cartilage and decreased hyaline and increased calcified cartilage thickness. Together, these changes predisposed the articular cartilage to enhanced OA severity in Adseverin mice who underwent surgical induction of OA. Adseverin chondrocyte RNA sequencing and in vitro studies together suggests that adseverin modulates cell viability and prevents mineralization. Thus, adseverin maintains articular chondrocyte phenotype and cartilage tissue homeostasis by preventing progression to hypertrophic differentiation in vivo. Adseverin may be chondroprotective and a potential therapeutic target.
Topics: Mice; Animals; Microfilament Proteins; Chondrocytes; Hedgehog Proteins; Osteoarthritis; Cell Differentiation; Cartilage, Articular; Actins
PubMed: 37540756
DOI: 10.1126/sciadv.adf1130 -
Journal of Cell Science May 2021Dynamic remodeling of the actin cytoskeleton is an essential feature for virtually all actin-dependent cellular processes, including cell migration, cell cycle... (Review)
Review
Dynamic remodeling of the actin cytoskeleton is an essential feature for virtually all actin-dependent cellular processes, including cell migration, cell cycle progression, chromatin remodeling and gene expression, and even the DNA damage response. An altered actin cytoskeleton is a structural hallmark associated with numerous pathologies ranging from cardiovascular diseases to immune disorders, neurological diseases and cancer. The actin cytoskeleton in cells is regulated through the orchestrated actions of a myriad of actin-binding proteins. In this Review, we provide a brief overview of the structure and functions of the actin-monomer-binding protein profilin-1 (Pfn1) and then discuss how dysregulated expression of Pfn1 contributes to diseases associated with the cardiovascular system.
Topics: Actin Cytoskeleton; Actins; Cardiovascular Diseases; Humans; Microfilament Proteins; Profilins
PubMed: 33961053
DOI: 10.1242/jcs.249060 -
Tumour Biology : the Journal of the... Jun 2017Actin-binding proteins are proteins that could bind to actin or actin fibers. As a member of actin-binding proteins, Transgelin-2 is expressed in smooth muscle cells and... (Review)
Review
Actin-binding proteins are proteins that could bind to actin or actin fibers. As a member of actin-binding proteins, Transgelin-2 is expressed in smooth muscle cells and non-smooth muscle cells, and its gene, TAGLN2, is differently expressed in all cells and tissues. The deregulation of Transgelin-2 is considered to be correlated with progression of many kinds of diseases, especially the development of malignant tumors, such as invasion, metastasis, and resistance, yet the function and mechanism of action of Transgelin-2 remain elusive. Therefore, we reviewed the basic characteristics and function of Transgelin-2 and its biological role in various types of diseases in order to provide the theoretical basis for further research and new perspectives on cancer development.
Topics: Actins; Biomarkers, Tumor; Carcinogenesis; Humans; Microfilament Proteins; Muscle Proteins; Neoplasms
PubMed: 28639888
DOI: 10.1177/1010428317702650 -
International Journal of Molecular... Mar 2022Ezrin is one of the members of the ezrin/radixin/moesin (ERM) family of proteins. It was originally discovered as an actin-binding protein in the microvilli structure... (Review)
Review
Ezrin is one of the members of the ezrin/radixin/moesin (ERM) family of proteins. It was originally discovered as an actin-binding protein in the microvilli structure about forty years ago. Since then, it has been revealed as a key protein with functions in a variety of fields including cell migration, survival, and signal transduction, as well as functioning as a structural component. Ezrin acts as a cross-linker of membrane proteins or phospholipids in the plasma membrane and the actin cytoskeleton. It also functions as a platform for signaling molecules at the cell surface. Moreover, ezrin is regarded as an important target protein in cancer diagnosis and therapy because it is a key protein involved in cancer progression and metastasis, and its high expression is linked to poor survival in many cancers. Small molecule inhibitors of ezrin have been developed and investigated as candidate molecules that suppress cancer metastasis. Here, we wish to comprehensively review the roles of ezrin from the pathophysiological points of view.
Topics: Actin Cytoskeleton; Actins; Cell Membrane; Cytoskeletal Proteins; Microfilament Proteins; Phosphoproteins
PubMed: 35328667
DOI: 10.3390/ijms23063246 -
Cell Communication and Signaling : CCS Jun 2018TRIO and F-actin-binding protein (TRIOBP) also referred to as Tara, was originally isolated as a cytoskeleton remodeling protein. TRIOBP-1 is important for regulating... (Review)
Review
TRIO and F-actin-binding protein (TRIOBP) also referred to as Tara, was originally isolated as a cytoskeleton remodeling protein. TRIOBP-1 is important for regulating F-actin filament reorganization. TRIOBP variants are broadly classified as variant-1 or - 4 and do not share exons. TRIOBP variant-5 contains all exons. Earlier studies indicated that TRIOBP-4/5 mutation is a pivotal element of autosomal recessive nonsyndromic hearing loss. However, recent studies provide clues that TRIOBP variants are associated with other human diseases including cancer and brain diseases. In this review, recent functional studies focusing on TRIOBP variants and its possible disease models are described.
Topics: Brain; Disease; Genetic Variation; Hearing Loss; Humans; Microfilament Proteins; Neoplasms
PubMed: 29890989
DOI: 10.1186/s12964-018-0237-y -
Histochemistry and Cell Biology Apr 2016Extensive research in the past decade has significantly broadened our view about the role actin plays in the life of the cell and added novel aspects to actin research.... (Review)
Review
Extensive research in the past decade has significantly broadened our view about the role actin plays in the life of the cell and added novel aspects to actin research. One of these new aspects is the discovery of the existence of nuclear actin which became evident only recently. Nuclear activities including transcriptional activation in the case of all three RNA polymerases, editing and nuclear export of mRNAs, and chromatin remodeling all depend on actin. It also became clear that there is a fine-tuned equilibrium between cytoplasmic and nuclear actin pools and that this balance is ensured by an export-import system dedicated to actin. After over half a century of research on conventional actin and its organizing partners in the cytoplasm, it was also an unexpected finding that the nucleus contains more than 30 actin-binding proteins and new classes of actin-related proteins which are not able to form filaments but had evolved nuclear-specific functions. The actin-binding and actin-related proteins in the nucleus have been linked to RNA transcription and processing, nuclear transport, and chromatin remodeling. In this paper, we attempt to provide an overview of the wide range of information that is now available about actin, actin-binding, and actin-related proteins in the nucleus.
Topics: Actins; Animals; Cell Nucleolus; Humans; Microfilament Proteins
PubMed: 26847179
DOI: 10.1007/s00418-015-1400-9