Absence of UV-induced non-homologous recombination in repair-deficient CHO cell lines transfected with ERCC genes

1996 ◽  
Vol 364 (2) ◽  
pp. 73-79 ◽  
Author(s):  
Giuseppe Rainaldi ◽  
Barbara Capecchi ◽  
Antonio Piras ◽  
Lucia Vatteroni
Author(s):  
M. Kruszewski ◽  
H. Kruszewska ◽  
H. Inaba ◽  
P. Jeggo ◽  
I. Szumiel

Cancers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 2547
Author(s):  
Keunsoo Kang ◽  
Yoonjung Choi ◽  
Hyeonjin Moon ◽  
Chaelin You ◽  
Minjin Seo ◽  
...  

RAD51 is a recombinase that plays a pivotal role in homologous recombination. Although the role of RAD51 in homologous recombination has been extensively studied, it is unclear whether RAD51 can be involved in gene regulation as a co-factor. In this study, we found evidence that RAD51 may contribute to the regulation of genes involved in the autophagy pathway with E-box proteins such as USF1, USF2, and/or MITF in GM12878, HepG2, K562, and MCF-7 cell lines. The canonical USF binding motif (CACGTG) was significantly identified at RAD51-bound cis-regulatory elements in all four cell lines. In addition, genome-wide USF1, USF2, and/or MITF-binding regions significantly coincided with the RAD51-associated cis-regulatory elements in the same cell line. Interestingly, the promoters of genes associated with the autophagy pathway, such as ATG3 and ATG5, were significantly occupied by RAD51 and regulated by RAD51 in HepG2 and MCF-7 cell lines. Taken together, these results unveiled a novel role of RAD51 and provided evidence that RAD51-associated cis-regulatory elements could possibly be involved in regulating autophagy-related genes with E-box binding proteins.


2021 ◽  
Vol 22 (10) ◽  
pp. 5218
Author(s):  
Tomu Kamijo ◽  
Takahiro Kaido ◽  
Masahiro Yoda ◽  
Shinpei Arai ◽  
Kazuyoshi Yamauchi ◽  
...  

We identified a novel heterozygous hypofibrinogenemia, γY278H (Hiroshima). To demonstrate the cause of reduced plasma fibrinogen levels (functional level: 1.12 g/L and antigenic level: 1.16 g/L), we established γY278H fibrinogen-producing Chinese hamster ovary (CHO) cells. An enzyme-linked immunosorbent assay demonstrated that synthesis of γY278H fibrinogen inside CHO cells and secretion into the culture media were not reduced. Then, we established an additional five variant fibrinogen-producing CHO cell lines (γL276P, γT277P, γT277R, γA279D, and γY280C) and conducted further investigations. We have already established 33 γ-module variant fibrinogen-producing CHO cell lines, including 6 cell lines in this study, but only the γY278H and γT277R cell lines showed disagreement, namely, recombinant fibrinogen production was not reduced but the patients’ plasma fibrinogen level was reduced. Finally, we performed fibrinogen degradation assays and demonstrated that the γY278H and γT277R fibrinogens were easily cleaved by plasmin whereas their polymerization in the presence of Ca2+ and “D:D” interaction was normal. In conclusion, our investigation suggested that patient γY278H showed hypofibrinogenemia because γY278H fibrinogen was secreted normally from the patient’s hepatocytes but then underwent accelerated degradation by plasmin in the circulation.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Laura Bryan ◽  
Michael Henry ◽  
Ronan M. Kelly ◽  
Christopher C. Frye ◽  
Matthew D. Osborne ◽  
...  

Abstract Background The ability to achieve high peak viable cell density earlier in CHO cell culture and maintain an extended cell viability throughout the production process is highly desirable to increase recombinant protein yields, reduce host cell impurities for downstream processing and reduce the cost of goods. In this study we implemented label-free LC-MS/MS proteomic profiling of IgG4 producing CHO cell lines throughout the duration of the cell culture to identify differentially expressed (DE) proteins and intracellular pathways associated with the high peak viable cell density (VCD) and extended culture VCD phenotypes. Results We identified key pathways in DNA replication, mitotic cell cycle and evasion of p53 mediated apoptosis in high peak VCD clonally derived cell lines (CDCLs). ER to Golgi vesicle mediated transport was found to be highly expressed in extended culture VCD CDCLs while networks involving endocytosis and oxidative stress response were significantly downregulated. Conclusion This investigation highlights key pathways for targeted engineering to generate desirable CHO cell phenotypes for biotherapeutic production.


1988 ◽  
Vol 38 (4) ◽  
pp. 269-278 ◽  
Author(s):  
M. van Heuvel ◽  
M. Govaert-Siemerink ◽  
I. J. Bosveld ◽  
E. G. Zwarthoff ◽  
J. Trapman

1990 ◽  
Vol 10 (12) ◽  
pp. 6755-6758
Author(s):  
B R Stanton ◽  
S W Reid ◽  
L F Parada

We have disrupted one allele of the N-myc locus in mouse embryonic stem (ES) cells by using homologous recombination techniques and have obtained germ line transmission of null N-myc ES cell lines with transmission of the null N-myc allele to the offspring. The creation of mice with a deficient N-myc allele will allow the generation of offspring bearing null N-myc alleles in both chromosomes and permit study of the role that this proto-oncogene plays in embryonic development.


BioTechniques ◽  
2018 ◽  
Vol 65 (1) ◽  
pp. 41-46 ◽  
Author(s):  
DC Soler ◽  
AE Young ◽  
A Vahedi-Faridi ◽  
TS McCormick

2016 ◽  
Author(s):  
Maureen M. Mundia ◽  
Alissa C. Magwood ◽  
Mark D. Baker

ABSTRACTIn this study, we utilized mouse hybridoma cell lines stably expressing ectopic wild-type Rad51, or the Rad51-K133A and Rad51-K133R catalytic mutants deficient in ATP binding and ATP hydrolysis, respectively, to investigate effects on the Rad51 nucleoprotein filament in vivo. Immunoprecipitation studies reveal interactions between ectopic wild-type Rad51, Rad51-K133A and Rad51-K133R and endogenous Rad51, Brca2 and p53 proteins. Importantly, the expression of Rad51-K133A and Rad51-K133R catalytic mutants (but not wild-type Rad51) targets endogenous Rad51, Brca2 and p53 proteins for proteasome-mediated degradation. Expression of Rad51-K133R significantly reduces nascent DNA synthesis (3’ polymerization) during homologous recombination (HR), but the effects of Rad51-K133A on 3’ polymerization are considerably more severe. Provision of additional wild-type Rad51 in cell lines expressing Rad51-K133A or Rad51-K133R does not restore diminished levels of endogenous Brca2, Rad51 or p53, nor restore the deficiency in 3’ polymerization. Cells expressing Rad51-K133A are also significantly reduced in their capacity to drive strand exchange through regions of heterology. Our results reveal an interesting mechanistic dichotomy in the way mutant Rad51-K133A and Rad51-K133R proteins influence 3’ polymerization and provide novel insight into the mechanism of their dominant-negative phenotypes.


2010 ◽  
Vol 26 (5) ◽  
pp. 1446-1454 ◽  
Author(s):  
Alison J. Porter ◽  
Alan J. Dickson ◽  
Andrew J. Racher
Keyword(s):  

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