Article
Biotechnology & Applied Microbiology
Merve Ceylan, Umit Yasar Kina, Ozgur Cakir, Neslihan Turgut Kara
Summary: Cycloastragenol (CAG) is a triterpenoid saponin compound synthesized by Astragalus species, with bioactivities including telomerase activation and telomere elongation. Our study showed that CAG increased transcript levels of positive regulators of the telomere/telomerase system in callus tissues of Arabidopsis thaliana.
PLANT CELL TISSUE AND ORGAN CULTURE
(2021)
Review
Biochemistry & Molecular Biology
Bibo Li
Summary: Telomere maintenance is crucial for genome stability and regulation of antigenic variation in microbial pathogens. Trypanosomes, such as T. brucei, use a unique DNA polymerase, PolIE, to coordinate the synthesis of telomere G- and C-strands, in contrast to mammalian cells that rely on telomere proteins. Understanding these mechanisms can aid in the development of treatments for diseases caused by these pathogens.
FRONTIERS IN MOLECULAR BIOSCIENCES
(2023)
Review
Cell Biology
Sarah W. Cai, Titia de Lange
Summary: In this review, the authors discuss the role of the CST-Polα/Primase complex in telomere length regulation. They highlight that this complex not only functions in strand synthesis but also controls telomerase to maintain telomere length. Additionally, they emphasize the importance of this complex in preventing telomeric disorders by replenishing lost sequences and determining telomere length.
GENES & DEVELOPMENT
(2023)
Article
Cell Biology
Daniel I. Sullivan, Fiona M. Bello, Agustin Gil Silva, Kevin M. Redding, Luca Giordano, Angela M. Hinchie, Kelly E. Loughridge, Ana L. Mora, Melanie Konigshoff, Brett A. Kaufman, Michael J. Jurczak, Jonathan K. Alder
Summary: Mitochondria play important roles in cellular metabolism and signaling. Defects in mitochondria caused by genetic or acquired factors can lead to various pathologies, including premature cellular senescence. In this study, we investigated the effects of dysfunctional telomeres on mitochondrial biogenesis and function during senescence. Our results showed that senescent cells had increased mitochondrial respiratory capacity and volume. Even in vivo, hepatocytes with dysfunctional telomeres maintained their mitochondrial respiratory capacity. The upregulation of genes related to mitochondria was observed during senescence in fibroblasts and hepatocytes. These findings suggest that mitochondrial function and activity are preserved in telomere dysfunction-induced senescence.
Review
Biochemistry & Molecular Biology
Semih Can Akincilar, Claire Hian Tzer Chan, Qin Feng Ng, Kerem Fidan, Vinay Tergaonkar
Summary: Telomerase activation is a common feature in cancer, but it does not directly correlate with telomere length. Aberrant expression of shelterin proteins and their release from shortened telomeres can further promote cancer through non-canonical mechanisms.
CELLULAR AND MOLECULAR LIFE SCIENCES
(2021)
Article
Biochemistry & Molecular Biology
Axel Karow, Monika Haubitz, Elisabeth Oppliger Leibundgut, Ingrid Helsen, Nicole Preising, Daniela Steiner, Tobias M. Dantonello, Roland A. Ammann, Jochen Roessler, Mutlu Kartal-Kaess, Alexander Roeth, Gabriela M. Baerlocher
Summary: The study found significant differences in telomere length and telomerase activity in lymphoblasts of patients with acute lymphoblastic leukemia. High-risk pediatric ALL patients had higher telomerase activity, and the telomerase inhibitor imetelstat showed significant dose-dependent apoptosis of B-ALL cells. Telomere length and telomerase activity may serve as complementary markers for identifying high-risk ALL patients, and telomerase inhibitors like imetelstat could enhance standard ALL treatment.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2021)
Article
Genetics & Heredity
Cory L. Holland, Brian A. Sanderson, James K. Titus, Monica F. Weis, Angelica M. Riojas, Eric Malczewskyj, Brian M. Wasko, L. Kevin Lewis
Summary: In this study, it was found that overexpression of the Est2 reverse transcriptase and TLC1 RNA template subunits of telomerase, but not other telomerase- and telomere-associated proteins, restored viability of yku mutant cells. Additionally, three catalytically inactive reverse transcriptase mutants were able to efficiently suppress cell death in yku cells. These findings suggest a replication-independent mechanism involving structural reinforcement of protective telomere cap structures in stabilizing chromosomes in yku mutants.
G3-GENES GENOMES GENETICS
(2021)
Article
Genetics & Heredity
Cory L. Holland, Brian A. Sanderson, James K. Titus, Monica F. Weis, Angelica M. Riojas, Eric Malczewskyj, Brian M. Wasko, L. Kevin Lewis
Summary: This study investigates how overexpression of telomerase suppresses the temperature sensitivity of yku mutants, showing that key components Est2 and TLC1 play crucial roles in restoring cell viability. The results suggest a model in which structural reinforcement of protective telomere cap structures stabilizes chromosomes in yku mutants via a replication-independent mechanism.
G3-GENES GENOMES GENETICS
(2021)
Review
Biochemistry & Molecular Biology
Jesmin Akter, Takehiko Kamijo
Summary: Telomere maintenance is crucial in neuroblastoma, with telomerase activation and ALT defining distinct subgroups and serving as potential therapeutic targets. Patients with high-risk neuroblastoma commonly carry genetic abnormalities that support telomere maintenance.
Editorial Material
Genetics & Heredity
Katarina Jurikova, Peter De Wulf, Emilio Cusanelli
Summary: Long noncoding RNAs derived from telomeres help to maintain telomere length and stability through various mechanisms, such as regulating telomerase activity and recombination-based telomere maintenance. New findings in yeast propose a model where telomere attachment to the nuclear envelope regulates telomere transcription and maintenance.
TRENDS IN GENETICS
(2021)
Article
Biochemistry & Molecular Biology
Alina Meeser, Christoph Bartenhagen, Lisa Werr, Anna-Maria Hellmann, Yvonne Kahlert, Nadine Hemstedt, Peter Nuernberg, Janine Altmueller, Sandra Ackermann, Barbara Hero, Thorsten Simon, Martin Peifer, Matthias Fischer, Carolina Rosswog
Summary: This study proposes a workflow for reliably detecting telomere maintenance mechanisms in neuroblastoma, which can be used in clinical routine for risk stratification and treatment allocation.
CELL AND BIOSCIENCE
(2022)
Article
Multidisciplinary Sciences
Julie Livingstone, Yu-Jia Shiah, Takafumi N. Yamaguchi, Lawrence E. Heisler, Vincent Huang, Robert Lesurf, Tsumugi Gebo, Benjamin Carlin, Stefan Eng, Erik Drysdale, Jeffrey Green, Theodorus van der Kwast, Robert G. Bristow, Michael Fraser, Paul C. Boutros
Summary: The study integrates telomere length, genomics, transcriptomics and proteomics in localized prostate cancer, revealing the links between telomere maintenance, disease drivers and clinical outcomes. Shorter tumor telomere lengths are associated with elevated genomic instability and genes involved in cell proliferation and signaling, while longer telomere lengths in non-tumor samples are associated with a lower rate of biochemical relapse.
NATURE COMMUNICATIONS
(2021)
Article
Biology
Alexander N. Malyavko, Olga A. Petrova, Maria Zvereva, Vladimir Polshakov, Olga A. Dontsova
Summary: This study reports the functional characterization of the Rif1 homologue from the methylotrophic thermotolerant budding yeast Hansenula polymorpha DL-1. The study reveals that Rif1 in H. polymorpha suppresses telomerase-dependent telomere elongation through direct DNA binding and association with the Ku heterodimer. It is also found that Rif1 binds Stn1 and promotes its accumulation at telomeres in H. polymorpha.
Article
Oncology
Jinglong Zhang, Fan Zhang, Kenneth I. Porter, Panshak P. Dakup, Shuwen Wang, Gavin P. Robertson, Shobhan Gaddameedhi, Jiyue Zhu
Summary: Telomerase activation is crucial for melanomagenesis, but is hindered by telomere dysfunction in mice. The study found that telomere dysfunction delays melanoma development and leads to DNA damage and genomic instability.
INTERNATIONAL JOURNAL OF CANCER
(2023)
Review
Oncology
Peter Lansdorp
Summary: The number of telomere repeats varies greatly between chromosomes, cells, and species. Loss of telomere repeats limits cell proliferation and contributes to aging, but the mechanisms behind these processes are still not fully understood. Further research is needed to investigate the role of factors such as damaged telomeric DNA, replication errors, chromatin structure, and secondary DNA structures in telomere dynamics in different cell types.
FRONTIERS IN ONCOLOGY
(2022)
Review
Biochemistry & Molecular Biology
Vivek Kumar Raxwal, Karel Riha
BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS
(2016)
Article
Multidisciplinary Sciences
J. Matthew Watson, Alexander Platzer, Anita Kazda, Svetlana Akimcheva, Sona Valuchova, Viktoria Nizhynska, Magnus Nordborg, Karel Riha
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2016)
Article
Multidisciplinary Sciences
Sona Valuchova, Jaroslav Fulnecek, Alexander P. Petrov, Konstantinos Tripsianes, Karel Riha
SCIENTIFIC REPORTS
(2016)
Article
Biochemistry & Molecular Biology
Sona Valuchova, Jaroslav Fulnecek, Zbynek Prokop, Peggy Stolt-Bergner, Eliska Janouskova, Ctirad Hofr, Karel Riha
Article
Plant Sciences
Claudio Capitao, Neha Shukla, Aneta Wandrolova, Ortrun Mittelsten Scheid, Karel Riha
FRONTIERS IN PLANT SCIENCE
(2018)
Article
Biology
Sona Valuchova, Pavlina Mikulkova, Jana Pecinkova, Jana Klimova, Michal Krumnikl, Petr Bainar, Stefan Heckmann, Pavel Tomancak, Karel Riha
Article
Genetics & Heredity
J. Matthew Watson, Johanna Trieb, Martina Troestl, Kyle Renfrew, Terezie Mandakova, Jaroslav Fulnecek, Dorothy E. Shippen, Karel Riha
Summary: The study demonstrates that telomeres of 400 bp are necessary and sufficient for Arabidopsis viability, with longer telomeres promoting telomerase processivity or recruitment. The findings suggest that telomeres long enough to form a t-loop constitute the minimal functional length.
Article
Biochemistry & Molecular Biology
Mariana Romeiro Motta, Xin'Ai Zhao, Martine Pastuglia, Katia Belcram, Farshad Roodbarkelari, Maki Komaki, Hirofumi Harashima, Shinichiro Komaki, Manoj Kumar, Petra Bulankova, Maren Heese, Karel Riha, David Bouchez, Arp Schnittger
Summary: Flowering plants contain multiple cyclin families, with B1-type cyclins playing a crucial role in cell cycle control during Arabidopsis development. Mutant analysis revealed complex overlapping requirements of B1-type cyclins, with CYCB1;2 being central. The double mutant cycb1;1 cycb1;2, although compromised in growth, provides a unique opportunity to study the function of B1-type cyclins at the organismic level.
Article
Genetics & Heredity
Claudio Capitao, Sorin Tanasa, Jaroslav Fulnecek, Vivek K. Raxwal, Svetlana Akimcheva, Petra Bulankova, Pavlina Mikulkova, Lucie Crhak Khaitova, Manikandan Kalidass, Inna Lermontova, Mittelsten Scheidid, Karel Riha
Summary: Meiosis in angiosperm plants is regulated by specific proteins, such as SMG7 and TDM1, in Arabidopsis. Mutants carrying the smg7-6 allele show reduced pollen production, but increasing the level of centromeric histone H3 promotes normal meiotic division. Differences in centromere size do not seem to be the key factor in centromere-mediated genome elimination.
Article
Biology
Vivek Kumar Raxwal, Somya Singh, Manu Agarwal, Karel Riha
Summary: The study revealed that new genes in rice have relatively low expression levels, possibly controlled by distal enhancers and chromatin conformation at their TSS; the chromatin in TSS regions may be remodeled in response to abiotic stress, indicating conditional expression of young genes. Furthermore, transcripts of young genes in Arabidopsis are prone to nonsense-mediated RNA decay, restricting their expression.
Article
Multidisciplinary Sciences
Albert Cairo, Anna Vargova, Neha Shukla, Claudio Capitao, Pavlina Mikulkova, Sona Valuchova, Jana Pecinkova, Petra Bulankova, Karel Riha
Summary: In Arabidopsis, the transition from meiosis to mitosis is driven by translation inhibition involving processing bodies. The meiosis-specific protein TDM1 is incorporated into processing bodies through interaction with SMG7, sequestering the main translation initiation complex and inhibiting translation. Chemical inhibition of translation can overcome the failure to terminate meiosis in tdm1 mutants. TDM1-containing processing bodies down-regulate meiotic transcripts to facilitate the transition of cell fates.
Review
Biochemistry & Molecular Biology
Vivek K. Raxwal, Karel Riha
Summary: NMD is a conserved quality control pathway that inhibits the expression of transcripts containing premature termination codon. It plays important roles in regulating gene expression and various physiological processes in plants.
BIOCHEMICAL SOCIETY TRANSACTIONS
(2023)
Article
Plant Sciences
Sorin Tanasa, Neha Shukla, Albert Cairo, Ranjani S. Ganji, Pavlina Mikulkova, Sona Valuchova, Vivek K. Raxwal, Claudio Capitao, Arp Schnittger, Zbynek Zdrahal, Karel Riha
Summary: Meiosis is a specialized cell division that reduces the number of chromosomes, followed by mitotic divisions to form haploid gametophytes in angiosperm plants. In Arabidopsis, the termination of meiosis and transition to gametophytic development are regulated by TDM1 and SMG7, which inhibit translation. Mutants deficient in this mechanism show aberrant nuclear divisions due to the failure to downregulate cyclin dependent kinases during meiotic exit. A mutation in cyclin-dependent kinase D;3 (CDKD;3) was identified as a suppressor that alleviates meiotic defects in smg7 deficient plants by preventing aberrant meiotic divisions or delaying their onset. CDKD;3 acts independently of CDKA;1 and interacts with proteins involved in cytokinesis, suggesting a complex role in cell cycle regulation.
Article
Biology
Stephan Eberhard, Sona Valuchova, Julie Ravat, Jaroslav Fulnecek, Pascale Jolivet, Sandrine Bujaldon, Stephane D. Lemaire, Francis-Andre Wollman, Maria Teresa Teixeira, Karel Riha, Zhou Xu
LIFE SCIENCE ALLIANCE
(2019)
Article
Plant Sciences
Peter Javorka, Vivek K. Raxwal, Jan Najvarek, Karel Riha