ADF/cofilin mediates actin cytoskeletal alterations in LLC-PK cells during ATP depletion

2003 ◽  
Vol 284 (4) ◽  
pp. F852-F862 ◽  
Author(s):  
Sharon L. Ashworth ◽  
Erica L. Southgate ◽  
Ruben M. Sandoval ◽  
Peter J. Meberg ◽  
James R. Bamburg ◽  
...  

Ischemic injury induces actin cytoskeleton disruption and aggregation, but mechanisms affecting these changes remain unclear. To determine the role of actin-depolymerizing factor (ADF)/ cofilin participation in ischemic-induced actin cytoskeletal breakdown, we utilized porcine kidney cultured cells, LLC-PKA4.8, and adenovirus containing wild-type (wt), constitutively active, and inactive Xenopus ADF/cofilin linked to green fluorescence protein [XAC(wt)-GFP] in an ATP depletion model. High adenoviral infectivity (70%) in LLC-PKA4.8 cells resulted in linearly increasing XAC(wt)-GFP and phosphorylated (p)XAC(wt)-GFP (inactive) expression. ATP depletion rapidly induced dephosphorylation, and, therefore, activation, of endogenous pcofilin as well as pXAC(wt)-GFP in conjunction with the formation of fluorescent XAC(wt)-GFP/actin aggregates and rods. No significant actin cytoskeletal alterations occurred with short-term ATP depletion of LLC-PKA4.8 cells expressing GFP or the constitutively inactive mutant XAC(S3E)-GFP, but cells expressing the constitutively active mutant demonstrated nearly instantaneous actin disruption with aggregate and rod formation. Confocal image three-dimensional volume reconstructions of normal and ATP-depleted LLC-PKA4.8 cells demonstrated that 25 min of ATP depletion induced a rapid increase in XAC(wt)-GFP apical and basal signal in addition to XAC-GFP/actin aggregate formation. These data demonstrate XAC(wt)-GFP participates in ischemia-induced actin cytoskeletal alterations and determines the rate and extent of these ATP depletion-induced cellular alterations.

2001 ◽  
Vol 276 (30) ◽  
pp. 28395-28401 ◽  
Author(s):  
Arihiro Tomura ◽  
Kiminobu Goto ◽  
Hidetaka Morinaga ◽  
Masatoshi Nomura ◽  
Taijiro Okabe ◽  
...  

2005 ◽  
Vol 170 (3) ◽  
pp. 455-464 ◽  
Author(s):  
Ji Luo ◽  
Seth J. Field ◽  
Jennifer Y. Lee ◽  
Jeffrey A. Engelman ◽  
Lewis C. Cantley

Phosphoinositide (PI) 3-kinase is required for most insulin and insulin-like growth factor (IGF) 1–dependent cellular responses. The p85 regulatory subunit of PI 3-kinase is required to mediate the insulin-dependent recruitment of PI 3-kinase to the plasma membrane, yet mice with reduced p85 expression have increased insulin sensitivity. To further understand the role of p85, we examined IGF-1–dependent translocation of p85α by using a green fluorescence protein (GFP)–tagged p85α (EGFP–p85α). In response to IGF-1, but not to PDGF signaling, EGFP–p85α translocates to discrete foci in the cell. These foci contain the insulin receptor substrate (IRS) 1 adaptor molecule, and their formation requires the binding of p85 to IRS-1. Surprisingly, monomeric p85 is preferentially localized to these foci compared with the p85–p110 dimer, and these foci are not sites of phosphatidylinositol-3,4,5-trisphosphate production. Ultrastructural analysis reveals that p85–IRS-1 foci are cytosolic protein complexes devoid of membrane. These results suggest a mechanism of signal down-regulation of IRS-1 that is mediated by monomeric p85 through the formation of a sequestration complex between p85 and IRS-1.


2021 ◽  
Author(s):  
Mahsa Babaei ◽  
Luisa Sartori ◽  
Alexey Karpukhin ◽  
Dmitrii Abashkin ◽  
Elena Matrosova ◽  
...  

Abstract Biotechnological production requires genetically stable recombinant strains. To ensure genomic stability, recombinant DNA is commonly integrated into the genome of the host strain. Multiple genetic tools have been developed for genomic integration into baker's yeast Saccharomyces cerevisiae. Previously, we had developed a vector toolkit EasyClone-MarkerFree for stable integration into eleven sites on chromosomes X, XI, and XII of S. cerevisiae. The markerless integration was enabled by CRISPR-Cas9 system. In this study, we have expanded the kit with eight additional intergenic integration sites located on different chromosomes. The integration efficiency into the new sites was above 80%. The expression level of green fluorescence protein (gfp) for all eight sites was similar or above XI-2 site from the original EasyClone-MarkerFree toolkit. The cellular growth was not affected by the integration into any of the new eight locations. The eight-vector expansion kit is available from AddGene.


1999 ◽  
Vol 27 (3) ◽  
pp. 471-484 ◽  
Author(s):  
Susanne Bremer ◽  
Maaike Van Dooren ◽  
Martin Paparella ◽  
Eugen Kossolov ◽  
Bernd Fleischmann ◽  
...  

Reproduction ◽  
2006 ◽  
Vol 131 (4) ◽  
pp. 681-687 ◽  
Author(s):  
Toshio Hani ◽  
Takanori Tachibe ◽  
Saburo Shingai ◽  
Nobuo Kamada ◽  
Otoya Ueda ◽  
...  

Cryopreservation of the ovaries is a useful technology for preservation of germ cells from experimental animals, because if the female founder is infertile or has mutated mitochondrial DNA, preservation of female germ cells is necessary. Although it is possible to cryopreserve immature mouse ovaries with a high degree of viability by vitrification with a mixture of several cryoprotectants, the viability of cryopreserved adult mouse ovaries is still unknown. Here, we investigated the viability of mouse ovaries at various ages after cryopreservation by vitrification techniques. Donor ovaries were collected from 10-day-, 4-week-, 10-week- and 7-month-old, female, nulliparous, green fluorescence protein (GFP)-transgenic mice and cryopreserved by vitrification. The vitrified-warmed ovaries were orthotopically transplanted to 4- or 10-week-old mice. GFP-positive pups were obtained in all experimental groups. In the 4-week-old recipients, the percentages of GFP-positive pups among the total pups from recipients transplanted with ovaries of 10-day-, 4-week-, 10-week- and 7-month-old donors were 44%, 9%, 12% and 4% respectively. In the 10-week-old recipients, the percentages of GFP-positive pups among the total pups from recipients transplanted with ovaries of 10-day-, 4-week-, 10-week- and 7-month-old donors were 36%, 16%, 2% and 9% respectively. Furthermore, GFP-positive pups also were obtained from recipients transplanted with ovaries of donors without normal estrous cyclicity. Our results indicate that cryopreservation of mouse ovaries by vitrification is a useful method for the preservation of female germ cells from mice of various ages.


Sign in / Sign up

Export Citation Format

Share Document