scholarly journals Author Correction: Regulation of local GTP availability controls RAC1 activity and cell invasion

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Anna Bianchi-Smiraglia ◽  
David W. Wolff ◽  
Daniel J. Marston ◽  
Zhiyong Deng ◽  
Zhannan Han ◽  
...  
Keyword(s):  
2021 ◽  
Vol 35 (S1) ◽  
Author(s):  
Amjad Aljagthmi ◽  
Mariana Cooke ◽  
Marcelo Kazanietz ◽  
Madhavi Kadakia
Keyword(s):  

2020 ◽  
Vol 34 (S1) ◽  
pp. 1-1
Author(s):  
Amjad Ahmed Aljagthmi ◽  
Mariana Cooke ◽  
Marcelo Kazanietz ◽  
Madhavi P. Kadakia
Keyword(s):  

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Anna Bianchi-Smiraglia ◽  
David W. Wolff ◽  
Daniel J. Marston ◽  
Zhiyong Deng ◽  
Zhannan Han ◽  
...  

AbstractPhysiological changes in GTP levels in live cells have never been considered a regulatory step of RAC1 activation because intracellular GTP concentration (determined by chromatography or mass spectrometry) was shown to be substantially higher than the in vitro RAC1 GTP dissociation constant (RAC1-GTP Kd). Here, by combining genetically encoded GTP biosensors and a RAC1 activity biosensor, we demonstrated that GTP levels fluctuating around RAC1-GTP Kd correlated with changes in RAC1 activity in live cells. Furthermore, RAC1 co-localized in protrusions of invading cells with several guanylate metabolism enzymes, including rate-limiting inosine monophosphate dehydrogenase 2 (IMPDH2), which was partially due to direct RAC1-IMPDH2 interaction. Substitution of endogenous IMPDH2 with IMPDH2 mutants incapable of binding RAC1 did not affect total intracellular GTP levels but suppressed RAC1 activity. Targeting IMPDH2 away from the plasma membrane did not alter total intracellular GTP pools but decreased GTP levels in cell protrusions, RAC1 activity, and cell invasion. These data provide a mechanism of regulation of RAC1 activity by local GTP pools in live cells.


2004 ◽  
Vol 42 (08) ◽  
Author(s):  
P Michl ◽  
M Ei'Bahrawy ◽  
R Poulsom ◽  
A Ramjaun ◽  
J Downward

Author(s):  
Islam Mohamed ◽  
Ahmed Moahmed ◽  
Mennatallah Abdelkader ◽  
Alaaeldin Saleh ◽  
Ala-Eddin Al-Moustafa

Introduction: Elaeagnus angustifolia (EA) is a medicinal plant that has been used for centuries in treating many human diseases, in the Middle East, including fever, amoebic dysentery, gastrointestinal problems. However, the effect of EA plant extract on human cancer progression especially oral malignancy has not been investigated yet. Thus, first we examined the effect of EA flower extract on angiogenesis in ovo, and on selected parameters in human oral cancer cells. Materials and methods: Chorioallantoic membranes (CAMs) of chicken embryos at 3-7 days of incubation were used to assess the effect EAflower plant extract on angiogenesis. Meanwhile, cell proliferation, soft agar, cell cycle, cell invasion and cell wounding assays were performed to explore the outcome of EA plant extract on FaDu and SCC25 oral cancer cell lines. On the other hand, western blot analysis was carried out to evaluate E-cadherin and Erk1/Erk2 expression and activation, respectively, in FaDu and SCC25 under the effect of EA extract. Results: Our data show that EA extract inhibits cell proliferation and colony formation, in addition to the initiation of Scell cycle arrest and reductionof G1/G2 phases. In parallel, EA extract provokes differentiation to an epithelial phenotype “mesenchymal-epithelial transition: MET” which is the opposite of “epithelial-mesenchymal transition, EMT”: an important event in cell invasion and metastasis. Thus, EA extract causes a dramatic decrease in cell motility and invasion abilities of FaDu and SCC25 cancer cells in comparison with their controls. These changes are accompanied by an up-regulation of E-cadherin expression. The molecular pathway analysis of the EA flower extract reveals that it can inhibit the phosphorylation of Erk1/Erk2, which could be behind the inhibition of angiogenesis, the initiation of MET event and the overexpression of E-cadherin. Conclusions: Our findings indicate that EA plant extract can downgrade human oral cancer progression by the inhibition of angiogenesis and cell invasion via Erk1/Erk2 signaling pathways.


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