MIB1-mediated degradation of WRN promotes cellular senescence in response to camptothecin treatment

Cellular and epigenetic perspective of protein stability and its implications in the biological system

Protein stability is a fundamental prerequisite in both experimental and therapeutic applications. Current advancements in high throughput experimental techniques and functional ontology approaches have elucidated that impairment in the structure and stability of proteins is intricately associated with the cause and cure of several diseases. Therefore, it is paramount to deeply understand the physical and molecular confounding factors governing the stability of proteins. In this review article, we comprehensively investigated the evolution of protein stability, examining its emergence over time, its relationship with organizational aspects and the experimental methods used to understand it. Furthermore, we have also emphasized the role of Epigenetics and its interplay with post-translational modifications (PTMs) in regulating the stability of proteins.

N6-methyladenosine-modified MIB1 promotes stemness properties and peritoneal metastasis of gastric cancer cells by ubiquitinating DDX3X

BACKGROUND

Peritoneal metastasis (PM), one of the most typical forms of metastasis in advanced gastric cancer (GC), indicates a poor prognosis. Exploring the potential molecular mechanism of PM is urgently necessary, as it has not been well studied. E3 ubiquitin ligase has been widely established to exert a biological function in various cancers, but its mechanism of action in GC with PM remains unknown.

METHODS

The effect of MIB1 on PM of GC was confirmed in vitro and in vivo. Co-immunoprecipitation (Co-IP) and mass spectrometry demonstrated the association between MIB1 and DDX3X. Western blot, flow cytometry and immunofluorescence determined that DDX3X was ubiquitylated by MIB1 and promoted stemness. We further confirmed that METTL3 promoted the up-regulation of MIB1 by RNA immunoprecipitation (RIP), luciferase reporter assay and other experiments.

RESULTS

We observed that the E3 ubiquitin ligase Mind bomb 1 (MIB1) was highly expressed in PMs, and patients with PM with high MIB1 expression showed a worse prognosis than those with low MIB1 expression. Mechanistically, our study demonstrated that the E3 ubiquitin ligase MIB1 promoted epithelial-mesenchymal transition (EMT) progression and stemness in GC cells by degrading DDX3X. In addition, METTL3 mediated m6A modification to stabilize MIB1, which required the m6A reader IGF2BP2.

CONCLUSIONS

Our study elucidated the specific molecular mechanism by which MIB1 promotes PM of GC, and suggested that targeting the METTL3-MIB1-DDX3X axis may be a promising therapeutic strategy for GC with PM.

The TDRD3-USP9X complex and MIB1 regulate TOP3B homeostasis and prevent deleterious TOP3B cleavage complexes

TOP3B is stabilized by TDRD3. Hypothesizing that TDRD3 recruits a deubiquitinase, we find that TOP3B interacts with USP9X via TDRD3. Inactivation of USP9X destabilizes TOP3B, and depletion of both TDRD3 and USP9X does not promote further TOP3B ubiquitylation. Additionally, we observe that MIB1 mediates the ubiquitylation and proteasomal degradation of TOP3B by directly interacting with TOP3B independently of TDRD3. Combined depletion of USP9X, TDRD3 and MIB1 causes no additional increase in TOP3B levels compared to MIB1 knockdown alone indicating that the TDRD3-USP9X complex works downstream of MIB1. To comprehend why cells degrade TOP3B in the absence of TDRD3, we measured TOP3Bccs. Lack of TDRD3 increases TOP3Bccs in DNA and RNA, and induced R-loops, γH2AX and growth defect. Biochemical experiments confirm that TDRD3 increases the turnover of TOP3B. Our work provides molecular insights into the mechanisms by which TDRD3 protect cells from deleterious TOP3Bccs which are otherwise removed by TRIM41.

Genomic characteristics and selection signals of Zhongshan ducks

The Zhongshan duck (ZSP) is a duck breed indigenous to China and is known for its moderate body size, strong disease resistance, tender meat, and little subcutaneous fat. However, the genomic basis of such excellent breeding characteristics remains poorly understood. Therefore, we generated whole-genomes of 58 ZSPs and 180 other indigenous Chinese ducks (60 Jinding ducks, 60 Shan Partridge ducks, and 60 Liancheng white ducks) and identified 10 560 032 single nucleotide polymorphisms and 1 334 893 structural variants. Based on genetic diversity and population structure indices, our results confirm that the ZSP is a unique germplasm resource. In addition, three reproduction-related genes (i.e., OAZ, AMH, and RLF) were located in highly differentiated regions between the ZSP and the other three duck breeds (Jinding duck; Liancheng White duck; Shan Partridge duck), suggesting that these genes may have a strong influence on egg production. Among these genes, AMH may have introgressed from an unknown species of the Anatidae family. We also identified other significant genes in the significantly differentiated window (i.e., 1% cut-off), some of which are responsible for growth and development (SEMA5B and MIB1), metabolism (EDEM3 and Xylb), skeletal system morphogenesis (bglap and MGP), and egg shape (ITPR2). These findings highlight the genetic characteristics of the ZSP that shape an array of its morphological traits. Overall, this study should facilitate a more fine-scale approach towards improving the ZSP and other indigenous ducks in China and even all over the world.

Acid ceramidase targeting pyruvate kinase affected trypsinogen activation in acute pancreatitis

Background

Acute pancreatitis is the sudden inflammation of the pancreas. Severe cases of acute pancreatitis are potentially fatal and have no specific treatment available. Premature trypsinogen activation could initiate acute pancreatitis. However, the mechanism underlying premature trypsinogen activation is not fully understood.

Methods

In this research, a primary pancreatic acinar cell or mouse acute pancreatitis model was constructed. The effect of acid ceramidase (ASAH1), which is responsible for sphingosine production, was investigated in trypsinogen activation in vitro and in vivo. Meanwhile, the proteins regulating ASAH1 or binding to sphingosine were also detected by co-immunoprecipitation followed by mass spectrometry.

Results

The results showed that ASAH1 increased in acute pancreatitis. Increased ASAH1 promoted the activation of trypsinogen and cathepsin B. On the contrary, ASAH1 downregulation inhibited trypsinogen and cathepsin B. Meanwhile, ASAH1 regulated the activity of trypsin and cathepsin B through sphingosine. Additionally, E3 ligase Mind bomb homolog 1 (MIB1) decreased in acute pancreatitis resulting in the decreased binding between MIB1 and ASAH1. Exogenous MIB1 diminished the elevation in trypsin activity induced by acute pancreatitis inducer. ASAH1 increased owing to the inhibition of the proteasome degradation by MIB1. In acute pancreatitis, sphingosine was found to bind to pyruvate kinase. Pyruvate kinase activation could reduce trypsinogen activation and mitochondrial reactive oxygen species (ROS) production induced by sphingosine.

Conclusions

In conclusion, during the process of acute pancreatitis, MIB1 downregulation led to ASAH1 upregulation, resulting in pyruvate kinase inhibition, followed by trypsinogen activation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s10020-022-00538-w.

Role of Paralogue of XRCC4 and XLF in DNA Damage Repair and Cancer Development

Non-homologous end joining (cNHEJ) is a major pathway to repair double-strand breaks (DSBs) in DNA. Several core cNHEJ are involved in the progress of the repair such as KU70 and 80, DNA-dependent protein kinase catalytic subunit (DNA-PKcs), Artemis, X-ray repair cross-complementing protein 4 (XRCC4), DNA ligase IV, and XRCC4-like factor (XLF). Recent studies have added a number of new proteins during cNHEJ. One of the newly identified proteins is Paralogue of XRCC4 and XLF (PAXX), which acts as a scaffold that is required to stabilize the KU70/80 heterodimer at DSBs sites and promotes the assembly and/or stability of the cNHEJ machinery. PAXX plays an essential role in lymphocyte development in XLF-deficient background, while XLF/PAXX double-deficient mouse embryo died before birth. Emerging evidence also shows a connection between the expression levels of PAXX and cancer development in human patients, indicating a prognosis role of the protein. This review will summarize and discuss the function of PAXX in DSBs repair and its potential role in cancer development.

E3 ubiquitin ligase mind bomb 1 overexpression reduces apoptosis and inflammation of cardiac microvascular endothelial cells in coronary microvascular dysfunction

BACKGROUND

The apoptosis and inflammation in cardiac microvascular endothelial cells (CMECs) promote the development of coronary microvascular dysfunction (CMD). The present study aimed to explore the role of E3 ubiquitin ligase mind bomb 1 (MIB1) in the apoptosis and inflammation in CMECs during CMD.

METHODS

In vivo, CMD in rats was induced by sodium laurate injection. In vitro, rat primary CMECs were stimulated by homocysteine (Hcy). The apoptosis of CMECs was measured using flow cytometry. The inflammation of CMECs was evaluated by the level of tumor necrosis factor alpha (TNF-α) and interleukin 1 beta (IL-1β). The interplay between MIB1 and mitogen-activated protein kinase kinase kinase 5 (map3k5, also called ASK1) was measured using Co-immunoprecipitation.

RESULTS

MIB1 expression was decreased and ASK1 expression was increased in the heart tissues of CMD rats and Hcy-treated CMECs. MIB1 overexpression decreased fibrinogen-like protein 2 (FGL2) secretion, inflammation, and apoptosis induced by Hcy in CMECs. Meanwhile, MIB1 overexpression decreased the protein levels of ASK1 and p38, while not affected ASK1 mRNA levels. The following mechanism experiments revealed that MIB1 downregulated ASK1 expression by increasing its ubiquitination. ASK1 overexpression reversed the inhibitory effect of MIB1 on FGL2 secretion, apoptosis, inflammation, and p38 activation in Hcy-treated CMECs. In CMD rats, MIB1 overexpression partly retarded CMD progression, manifesting as increased coronary capillary density and decreased microthrombi formation.

CONCLUSION

MIB1 overexpression relieved apoptosis and inflammation of CMECs during CMD by targeting the ASK1/p38 pathway.

MicroRNA‑195‑5p is associated with cell proliferation, migration and invasion in prostate cancer and targets MIB1

Mind bomb 1 (MIB1) is a well‑known E3 ubiquitin ligase. MicroRNAs (miRNAs/miRs) have been found to serve important functions in cancer cell physiology. However, the clinical significance and biological function of MIB1 and miRNAs in prostate cancer (PCa) are yet to be fully elucidated. The current study predicted the interaction between MIB1 and miR‑195‑5p using TargetScan, and the results were confirmed by performing a dual‑luciferase reporter assay. The mRNA expression level of MIB1 and miR‑195‑5p in PCa and adjacent normal tissues, and PCa cell lines was detected using reverse transcription‑quantitative PCR. Cell Counting Kit‑8 and Transwell assays were used to measure the proliferation, and migration and invasion of VCaP and DU145 PCa cell lines, respectively, while western blot analysis was used to detect the protein expression level of MIB1. The results revealed that the mRNA expression level of MIB1 was increased, while the mRNA expression level of miR‑195‑5p was decreased in PCa tissues (P<0.001 and P<0.01, respectively) and in various cell lines, including PC‑3 (P<0.001 and P<0.05, respectively), VCaP (P<0.001 and P<0.01, respectively), 22Rv1 (P<0.001 and P<0.05, respectively), DU145 (P<0.001 and P<0.01, respectively) and LNCaP (P<0.001 and P<0.05, respectively). miR‑195‑5p mimics rescued the inhibitory effects caused by knockdown of MIB1 on cell proliferation, migration and invasion in the VCaP and DU145 cell lines. In addition, MIB1 overexpression restored the miR‑195‑5p overexpression‑induced repression of cell proliferation and invasion. The current study revealed that the MIB1 gene was an effector of cell proliferation, migration and invasion in PCa cell lines. Furthermore, miR‑195‑5p may regulate PCa cell proliferation and invasion by regulating MIB1, indicating its potential therapeutic application for PCa in the future.

The E3 Ligase MIB1 Promotes Proteasomal Degradation of NRF2 and Sensitizes Lung Cancer Cells to Ferroptosis

Dysregulation of Notch signaling has been implicated in cellular transformation and tumorigenesis in a variety of cancers while potential roles of MIB1, an E3 ubiquitin ligase required for efficient Notch activation, remains to be investigated. We analyzed MIB1 expression levels in tumor samples and performed gain-of-function and loss-of-function studies in cell lines to investigate potential roles of MIB1 in epithelial-to-mesenchymal transition (EMT), cell migration, and cell survival. We found that overexpression of MIB1 is detected in a subset of lung squamous carcinoma and adenocarcinoma samples and negative correlation is observed between MIB1 expression and overall patient survival. Ectopic expression of MIB1 in A549 cells induces EMT and stimulates cell migration via a Notch-dependent pathway. Meanwhile, MIB1 stimulates the degradation of nuclear factor erythroid 2-related factor 2 (NRF2) in a Notch-independent manner and disrupts the antioxidant capacity of cells, rendering them more sensitive to inducers of ferroptosis. On the other hand, MIB1 knockout induces accumulation of NRF2 and resistance to ferroptosis. Collectively, these results indicate that MIB1 may function as a positive regulator of ferroptosis through targeted degradation of the master antioxidant transcription factor NRF2. IMPLICATIONS: This study identifies a MIB1-induced proteasomal degradation pathway for NRF2 and reveals elevated ferroptosis sensitivity in MIB1-overexpressing cells which may provide novel insights into the treatment of MIB1-overexpressing cancers.

MIB1 upregulates IQGAP1 and promotes pancreatic cancer progression by inducing ST7 degradation

Despite recent progress in cancer treatment, the prognosis of patients with pancreatic cancer still remains poor. Pancreatic tumors are reported to display high molecular heterogeneity. Elucidating the molecular mechanisms underlying pancreatic cancer progression is essential for improving patient treatment and survival. The overexpression of E3 ubiquitin ligase mind bomb 1 (MIB1) was previously described in pancreatic cancer cells, where it enhanced tumor cell proliferation. However, the role of MIB1 in pancreatic cancer progression remains elusive. In the present study, we confirmed that MIB1 expression is elevated in pancreatic cancer tissues and that high levels of MIB associate with unfavorable prognosis. Overexpression of MIB1 enhanced proliferation and invasion of pancreatic cancer cells both in vitro and in vivo. We further investigated the molecular mechanisms downstream of MIB1 and observed for the first time that MIB1 targets suppressor of tumorigenicity 7 protein (ST7), previously described as suppressor of tumorigenicity, for proteasomal degradation. Furthermore, we found that ST7 suppressed tumor growth by downregulating IQ motif containing GTPase activating protein 1 (IQGAP1) in pancreatic tumor cells. Thus, these data show that MIB1 promotes pancreatic cancer progression by inducing ST7 degradation followed by downregulation of IQGAP1 in pancreatic cancer cells. In conclusion, our research shows that the MIB1/ST7/IQGAP1 axis is essential for pancreatic cancer progression, and MIB1 inhibition may serve as a novel therapeutic strategy in patients with pancreatic cancer.

Human RecQ Helicases in DNA Double-Strand Break Repair

RecQ DNA helicases are a conserved protein family found in bacteria, fungus, plants, and animals. These helicases play important roles in multiple cellular functions, including DNA replication, transcription, DNA repair, and telomere maintenance. Humans have five RecQ helicases: RECQL1, Bloom syndrome protein (BLM), Werner syndrome helicase (WRN), RECQL4, and RECQL5. Defects in BLM and WRN cause autosomal disorders: Bloom syndrome (BS) and Werner syndrome (WS), respectively. Mutations in RECQL4 are associated with three genetic disorders, Rothmund–Thomson syndrome (RTS), Baller–Gerold syndrome (BGS), and RAPADILINO syndrome. Although no genetic disorders have been reported due to loss of RECQL1 or RECQL5, dysfunction of either gene is associated with tumorigenesis. Multiple genetically independent pathways have evolved that mediate the repair of DNA double-strand break (DSB), and RecQ helicases play pivotal roles in each of them. The importance of DSB repair is supported by the observations that defective DSB repair can cause chromosomal aberrations, genomic instability, senescence, or cell death, which ultimately can lead to premature aging, neurodegeneration, or tumorigenesis. In this review, we will introduce the human RecQ helicase family, describe in detail their roles in DSB repair, and provide relevance between the dysfunction of RecQ helicases and human diseases.

Human RecQ Helicases in DNA Double-Strand Break Repair

RecQ DNA helicases are a conserved protein family found in bacteria, fungus, plants, and animals. These helicases play important roles in multiple cellular functions, including DNA replication, transcription, DNA repair, and telomere maintenance. Humans have five RecQ helicases: RECQL1, Bloom syndrome protein (BLM), Werner syndrome helicase (WRN), RECQL4, and RECQL5. Defects in BLM and WRN cause autosomal disorders: Bloom syndrome (BS) and Werner syndrome (WS), respectively. Mutations in RECQL4 are associated with three genetic disorders, Rothmund–Thomson syndrome (RTS), Baller–Gerold syndrome (BGS), and RAPADILINO syndrome. Although no genetic disorders have been reported due to loss of RECQL1 or RECQL5, dysfunction of either gene is associated with tumorigenesis. Multiple genetically independent pathways have evolved that mediate the repair of DNA double-strand break (DSB), and RecQ helicases play pivotal roles in each of them. The importance of DSB repair is supported by the observations that defective DSB repair can cause chromosomal aberrations, genomic instability, senescence, or cell death, which ultimately can lead to premature aging, neurodegeneration, or tumorigenesis. In this review, we will introduce the human RecQ helicase family, describe in detail their roles in DSB repair, and provide relevance between the dysfunction of RecQ helicases and human diseases.

Human RecQ Helicases in DNA Double-Strand Break Repair

RecQ DNA helicases are a conserved protein family found in bacteria, fungus, plants, and animals. These helicases play important roles in multiple cellular functions, including DNA replication, transcription, DNA repair, and telomere maintenance. Humans have five RecQ helicases: RECQL1, Bloom syndrome protein (BLM), Werner syndrome helicase (WRN), RECQL4, and RECQL5. Defects in BLM and WRN cause autosomal disorders: Bloom syndrome (BS) and Werner syndrome (WS), respectively. Mutations in RECQL4 are associated with three genetic disorders, Rothmund–Thomson syndrome (RTS), Baller–Gerold syndrome (BGS), and RAPADILINO syndrome. Although no genetic disorders have been reported due to loss of RECQL1 or RECQL5, dysfunction of either gene is associated with tumorigenesis. Multiple genetically independent pathways have evolved that mediate the repair of DNA double-strand break (DSB), and RecQ helicases play pivotal roles in each of them. The importance of DSB repair is supported by the observations that defective DSB repair can cause chromosomal aberrations, genomic instability, senescence, or cell death, which ultimately can lead to premature aging, neurodegeneration, or tumorigenesis. In this review, we will introduce the human RecQ helicase family, describe in detail their roles in DSB repair, and provide relevance between the dysfunction of RecQ helicases and human diseases.

Human RecQ Helicases in DNA Double-Strand Break Repair

RecQ DNA helicases are a conserved protein family found in bacteria, fungus, plants, and animals. These helicases play important roles in multiple cellular functions, including DNA replication, transcription, DNA repair, and telomere maintenance. Humans have five RecQ helicases: RECQL1, Bloom syndrome protein (BLM), Werner syndrome helicase (WRN), RECQL4, and RECQL5. Defects in BLM and WRN cause autosomal disorders: Bloom syndrome (BS) and Werner syndrome (WS), respectively. Mutations in RECQL4 are associated with three genetic disorders, Rothmund–Thomson syndrome (RTS), Baller–Gerold syndrome (BGS), and RAPADILINO syndrome. Although no genetic disorders have been reported due to loss of RECQL1 or RECQL5, dysfunction of either gene is associated with tumorigenesis. Multiple genetically independent pathways have evolved that mediate the repair of DNA double-strand break (DSB), and RecQ helicases play pivotal roles in each of them. The importance of DSB repair is supported by the observations that defective DSB repair can cause chromosomal aberrations, genomic instability, senescence, or cell death, which ultimately can lead to premature aging, neurodegeneration, or tumorigenesis. In this review, we will introduce the human RecQ helicase family, describe in detail their roles in DSB repair, and provide relevance between the dysfunction of RecQ helicases and human diseases.

Human RecQ Helicases in DNA Double-Strand Break Repair

RecQ DNA helicases are a conserved protein family found in bacteria, fungus, plants, and animals. These helicases play important roles in multiple cellular functions, including DNA replication, transcription, DNA repair, and telomere maintenance. Humans have five RecQ helicases: RECQL1, Bloom syndrome protein (BLM), Werner syndrome helicase (WRN), RECQL4, and RECQL5. Defects in BLM and WRN cause autosomal disorders: Bloom syndrome (BS) and Werner syndrome (WS), respectively. Mutations in RECQL4 are associated with three genetic disorders, Rothmund–Thomson syndrome (RTS), Baller–Gerold syndrome (BGS), and RAPADILINO syndrome. Although no genetic disorders have been reported due to loss of RECQL1 or RECQL5, dysfunction of either gene is associated with tumorigenesis. Multiple genetically independent pathways have evolved that mediate the repair of DNA double-strand break (DSB), and RecQ helicases play pivotal roles in each of them. The importance of DSB repair is supported by the observations that defective DSB repair can cause chromosomal aberrations, genomic instability, senescence, or cell death, which ultimately can lead to premature aging, neurodegeneration, or tumorigenesis. In this review, we will introduce the human RecQ helicase family, describe in detail their roles in DSB repair, and provide relevance between the dysfunction of RecQ helicases and human diseases.

Human RecQ Helicases in DNA Double-Strand Break Repair

RecQ DNA helicases are a conserved protein family found in bacteria, fungus, plants, and animals. These helicases play important roles in multiple cellular functions, including DNA replication, transcription, DNA repair, and telomere maintenance. Humans have five RecQ helicases: RECQL1, Bloom syndrome protein (BLM), Werner syndrome helicase (WRN), RECQL4, and RECQL5. Defects in BLM and WRN cause autosomal disorders: Bloom syndrome (BS) and Werner syndrome (WS), respectively. Mutations in RECQL4 are associated with three genetic disorders, Rothmund–Thomson syndrome (RTS), Baller–Gerold syndrome (BGS), and RAPADILINO syndrome. Although no genetic disorders have been reported due to loss of RECQL1 or RECQL5, dysfunction of either gene is associated with tumorigenesis. Multiple genetically independent pathways have evolved that mediate the repair of DNA double-strand break (DSB), and RecQ helicases play pivotal roles in each of them. The importance of DSB repair is supported by the observations that defective DSB repair can cause chromosomal aberrations, genomic instability, senescence, or cell death, which ultimately can lead to premature aging, neurodegeneration, or tumorigenesis. In this review, we will introduce the human RecQ helicase family, describe in detail their roles in DSB repair, and provide relevance between the dysfunction of RecQ helicases and human diseases.

Human RecQ Helicases in DNA Double-Strand Break Repair

RecQ DNA helicases are a conserved protein family found in bacteria, fungus, plants, and animals. These helicases play important roles in multiple cellular functions, including DNA replication, transcription, DNA repair, and telomere maintenance. Humans have five RecQ helicases: RECQL1, Bloom syndrome protein (BLM), Werner syndrome helicase (WRN), RECQL4, and RECQL5. Defects in BLM and WRN cause autosomal disorders: Bloom syndrome (BS) and Werner syndrome (WS), respectively. Mutations in RECQL4 are associated with three genetic disorders, Rothmund–Thomson syndrome (RTS), Baller–Gerold syndrome (BGS), and RAPADILINO syndrome. Although no genetic disorders have been reported due to loss of RECQL1 or RECQL5, dysfunction of either gene is associated with tumorigenesis. Multiple genetically independent pathways have evolved that mediate the repair of DNA double-strand break (DSB), and RecQ helicases play pivotal roles in each of them. The importance of DSB repair is supported by the observations that defective DSB repair can cause chromosomal aberrations, genomic instability, senescence, or cell death, which ultimately can lead to premature aging, neurodegeneration, or tumorigenesis. In this review, we will introduce the human RecQ helicase family, describe in detail their roles in DSB repair, and provide relevance between the dysfunction of RecQ helicases and human diseases.

Human RecQ Helicases in DNA Double-Strand Break Repair

RecQ DNA helicases are a conserved protein family found in bacteria, fungus, plants, and animals. These helicases play important roles in multiple cellular functions, including DNA replication, transcription, DNA repair, and telomere maintenance. Humans have five RecQ helicases: RECQL1, Bloom syndrome protein (BLM), Werner syndrome helicase (WRN), RECQL4, and RECQL5. Defects in BLM and WRN cause autosomal disorders: Bloom syndrome (BS) and Werner syndrome (WS), respectively. Mutations in RECQL4 are associated with three genetic disorders, Rothmund–Thomson syndrome (RTS), Baller–Gerold syndrome (BGS), and RAPADILINO syndrome. Although no genetic disorders have been reported due to loss of RECQL1 or RECQL5, dysfunction of either gene is associated with tumorigenesis. Multiple genetically independent pathways have evolved that mediate the repair of DNA double-strand break (DSB), and RecQ helicases play pivotal roles in each of them. The importance of DSB repair is supported by the observations that defective DSB repair can cause chromosomal aberrations, genomic instability, senescence, or cell death, which ultimately can lead to premature aging, neurodegeneration, or tumorigenesis. In this review, we will introduce the human RecQ helicase family, describe in detail their roles in DSB repair, and provide relevance between the dysfunction of RecQ helicases and human diseases.

Human RecQ Helicases in DNA Double-Strand Break Repair

RecQ DNA helicases are a conserved protein family found in bacteria, fungus, plants, and animals. These helicases play important roles in multiple cellular functions, including DNA replication, transcription, DNA repair, and telomere maintenance. Humans have five RecQ helicases: RECQL1, Bloom syndrome protein (BLM), Werner syndrome helicase (WRN), RECQL4, and RECQL5. Defects in BLM and WRN cause autosomal disorders: Bloom syndrome (BS) and Werner syndrome (WS), respectively. Mutations in RECQL4 are associated with three genetic disorders, Rothmund–Thomson syndrome (RTS), Baller–Gerold syndrome (BGS), and RAPADILINO syndrome. Although no genetic disorders have been reported due to loss of RECQL1 or RECQL5, dysfunction of either gene is associated with tumorigenesis. Multiple genetically independent pathways have evolved that mediate the repair of DNA double-strand break (DSB), and RecQ helicases play pivotal roles in each of them. The importance of DSB repair is supported by the observations that defective DSB repair can cause chromosomal aberrations, genomic instability, senescence, or cell death, which ultimately can lead to premature aging, neurodegeneration, or tumorigenesis. In this review, we will introduce the human RecQ helicase family, describe in detail their roles in DSB repair, and provide relevance between the dysfunction of RecQ helicases and human diseases.

Human RecQ Helicases in DNA Double-Strand Break Repair

RecQ DNA helicases are a conserved protein family found in bacteria, fungus, plants, and animals. These helicases play important roles in multiple cellular functions, including DNA replication, transcription, DNA repair, and telomere maintenance. Humans have five RecQ helicases: RECQL1, Bloom syndrome protein (BLM), Werner syndrome helicase (WRN), RECQL4, and RECQL5. Defects in BLM and WRN cause autosomal disorders: Bloom syndrome (BS) and Werner syndrome (WS), respectively. Mutations in RECQL4 are associated with three genetic disorders, Rothmund–Thomson syndrome (RTS), Baller–Gerold syndrome (BGS), and RAPADILINO syndrome. Although no genetic disorders have been reported due to loss of RECQL1 or RECQL5, dysfunction of either gene is associated with tumorigenesis. Multiple genetically independent pathways have evolved that mediate the repair of DNA double-strand break (DSB), and RecQ helicases play pivotal roles in each of them. The importance of DSB repair is supported by the observations that defective DSB repair can cause chromosomal aberrations, genomic instability, senescence, or cell death, which ultimately can lead to premature aging, neurodegeneration, or tumorigenesis. In this review, we will introduce the human RecQ helicase family, describe in detail their roles in DSB repair, and provide relevance between the dysfunction of RecQ helicases and human diseases.

Human RecQ Helicases in DNA Double-Strand Break Repair

RecQ DNA helicases are a conserved protein family found in bacteria, fungus, plants, and animals. These helicases play important roles in multiple cellular functions, including DNA replication, transcription, DNA repair, and telomere maintenance. Humans have five RecQ helicases: RECQL1, Bloom syndrome protein (BLM), Werner syndrome helicase (WRN), RECQL4, and RECQL5. Defects in BLM and WRN cause autosomal disorders: Bloom syndrome (BS) and Werner syndrome (WS), respectively. Mutations in RECQL4 are associated with three genetic disorders, Rothmund-Thomson syndrome (RTS), Baller-Gerold syndrome (BGS), and RAPADILINO syndrome. Although no genetic disorders have been reported due to loss of RECQL1 or RECQL5, dysfunction of either gene is associated with tumorigenesis. Multiple genetically independent pathways have evolved that mediate the repair of DNA double-strand break (DSB), and RecQ helicases play pivotal roles in each of them. The importance of DSB repair is supported by the observations that defective DSB repair can cause chromosomal aberrations, genomic instability, senescence, or cell death, which ultimately can lead to premature aging, neurodegeneration, or tumorigenesis. In this review, we will introduce the human RecQ helicase family, describe in detail their roles in DSB repair, and provide relevance between the dysfunction of RecQ helicases and human diseases.