Biochemical control systems operating in the early hours of germination

1983 ◽  
Vol 61 (12) ◽  
pp. 3568-3577 ◽  
Author(s):  
Daphne J. Osborne

This review describes very early biochemical events during imbibition in seeds. It considers the control systems that regulate the production of nucleic acids and proteins when the dry seed first imbibes water. During the ageing of embryos in the dry state, DNA is progressively fragmented with an accumulation of single-stranded breaks. The critical role of DNA repair early in imbibition is considered in the context of genetic integrity of the nuclear template and successful germination.

2021 ◽  
Author(s):  
Tomoko Tanaka ◽  
Shinobu Hirai ◽  
Hiroyuki Manabe ◽  
Kentaro Endo ◽  
Hiroko Shimbo ◽  
...  

Aging involves a decline in physiology which is a natural event in all living organisms. An accumulation of DNA damage contributes to the progression of aging. DNA is continually damaged by exogenous sources and endogenous sources. If the DNA repair pathway operates normally, DNA damage is not life threatening. However, impairments of the DNA repair pathway may result in an accumulation of DNA damage, which has a harmful effect on health and causes an onset of pathology. RP58, a zinc-finger transcriptional repressor, plays a critical role in cerebral cortex formation. Recently, it has been reported that the expression level of RP58 decreases in the aged human cortex. Furthermore, the role of RP58 in DNA damage is inferred by the involvement of DNMT3, which acts as a co-repressor for RP58, in DNA damage. Therefore, RP58 may play a crucial role in the DNA damage associated with aging. In the present study, we investigated the role of RP58 in aging. We used RP58 hetero-knockout and wild-type mice in adolescence, adulthood, or old age. We performed immunohistochemistry to determine whether microglia and DNA damage markers responded to the decline in RP58 levels. Furthermore, we performed an object location test to measure cognitive function, which decline with age. We found that the wild-type mice showed an increase in single-stranded DNA and gamma-H2AX foci. These results indicate an increase in DNA damage or dysfunction of DNA repair mechanisms in the hippocampus as age-related changes. Furthermore, we found that, with advancing age, both the wild-type and hetero-knockout mice showed an impairment of spatial memory for the object and increase in reactive microglia in the hippocampus. However, the RP58 hetero-knockout mice showed these symptoms earlier than the wild-type mice did. These results suggest that a decline in RP58 level may lead to the progression of aging.


2014 ◽  
Vol 5 (1) ◽  
Author(s):  
Kenbun Sone ◽  
Lianhua Piao ◽  
Makoto Nakakido ◽  
Koji Ueda ◽  
Thomas Jenuwein ◽  
...  

Oncogene ◽  
2021 ◽  
Author(s):  
Zied Boudhraa ◽  
Kossay Zaoui ◽  
Hubert Fleury ◽  
Maxime Cahuzac ◽  
Sophie Gilbert ◽  
...  

AbstractWhile aneuploidy is a main enabling characteristic of cancers, it also creates specific vulnerabilities. Here we demonstrate that Ran inhibition targets epithelial ovarian cancer (EOC) survival through its characteristic aneuploidy. We show that induction of aneuploidy in rare diploid EOC cell lines or normal cells renders them highly dependent on Ran. We also establish an inverse correlation between Ran and the tumor suppressor NR1D1 and reveal the critical role of Ran/NR1D1 axis in aneuploidy-associated endogenous DNA damage repair. Mechanistically, we show that Ran, through the maturation of miR4472, destabilizes the mRNA of NR1D1 impacting several DNA repair pathways. We showed that NR1D1 interacts with both PARP1 and BRCA1 leading to the inhibition of DNA repair. Concordantly, loss of Ran was associated with NR1D1 induction, accumulation of DNA damages, and lethality of aneuploid EOC cells. Our findings suggest a synthetic lethal strategy targeting aneuploid cells based on their dependency to Ran.


2020 ◽  
Vol 13 (1) ◽  
pp. 25-37
Author(s):  
Tulsi Jayakumar

A critical challenge in the long-term survival and growth of family businesses is the adoption of professionalisation. The latter itself, when viewed as a multi-dimensional construct, would involve a critical role assigned to HR and HR control systems. This article then seeks to undertake an exploratory research to understand the current reality and the future perspectives of professionalisation in Indian family businesses through the lens of HR and HR control systems. Six caselets explore the experiences of six representative family businesses with regard to their professionalisation journey. The article finds that while the next-generation views professionalisation as imperative for scaling up, HR is still in its infancy stage in these Indian family firms. This would have ramifications for the outcomes of such professionalisation. The article concludes that HR would need to be assigned the role of a regenerative function, rather than a back-end administrative role that seems to be the current reality.


Cells ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1205
Author(s):  
Troy A. Kervin ◽  
Michael Overduin

The genetic code that dictates how nucleic acids are translated into proteins is well known, however, the code through which proteins recognize membranes remains mysterious. In eukaryotes, this code is mediated by hundreds of membrane readers that recognize unique phosphatidylinositol phosphates (PIPs), which demark organelles to initiate localized trafficking and signaling events. The only superfamily which specifically detects all seven PIPs are the Phox homology (PX) domains. Here, we reveal that throughout evolution, these readers are universally regulated by the phosphorylation of their PIP binding surfaces based on our analysis of existing and modelled protein structures and phosphoproteomic databases. These PIP-stops control the selective targeting of proteins to organelles and are shown to be key determinants of high-fidelity PIP recognition. The protein kinases responsible include prominent cancer targets, underscoring the critical role of regulated membrane readership.


2014 ◽  
Vol 25 (2) ◽  
pp. 213-221 ◽  
Author(s):  
Jing Yan Krzeszinski ◽  
Vitnary Choe ◽  
Jia Shao ◽  
Xin Bao ◽  
Haili Cheng ◽  
...  

Although ubiquitin receptor Rad23 has been implicated in bringing ubiquitylated p53 to the proteasome, how Rad23 recognizes p53 remains unclear. We demonstrate that XPC, a Rad23-binding protein, regulates p53 turnover. p53 protein in XPC-deficient cells remains ubiquitylated, but its association with the proteasome is drastically reduced, indicating that XPC regulates a postubiquitylation event. Furthermore, we found that XPC participates in the MDM2-mediated p53 degradation pathway via direct interaction with MDM2. XPC W690S pathogenic mutant is specifically defective for MDM2 binding and p53 degradation. p53 is known to become stabilized following UV irradiation but can be rendered unstable by XPC overexpression, underscoring a critical role of XPC in p53 regulation. Elucidation of the proteolytic role of XPC in cancer cells will help to unravel the detailed mechanisms underlying the coordination of DNA repair and proteolysis.


2016 ◽  
Vol 8s1 ◽  
pp. BIC.S36679 ◽  
Author(s):  
Bratati Ganguly ◽  
Sonia C. Dolfi ◽  
Lorna Rodriguez-Rodriguez ◽  
Shridar Ganesan ◽  
Kim M. Hirshfield

Defects in DNA repair lead to genomic instability and play a critical role in cancer development. Understanding the process by which DNA damage repair is altered or bypassed in cancer may identify novel therapeutic targets and lead to improved patient outcomes. Poly(adenosine diphosphateribose) polymerase 1 (PARP1) has an important role in DNA repair, and novel therapeutics targeting PARP1 have been developed to treat cancers with defective DNA repair pathways. Despite treatment successes with PARP inhibitors (PARPi), intrinsic and acquired resistances have been observed. Preclinical studies and clinical trials in cancer suggest that combination therapy using PARPi and platinating agents is more effective than monotherapy in circumventing drug resistance mechanisms. Additionally, identification of biomarkers in response to PARPi will lead to improved patient selection for targeted cancer treatment. Recent technological advances have provided the necessary tools to examine many potential avenues to develop such biomarkers. This review examines the mechanistic rationale of PARP inhibition and potential biomarkers in their development for personalized therapy.


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