Expression of a dominant negative retinoic acid receptor ? in Xenopus embryos leads to partial resistance to retinoic acid

1994 ◽  
Vol 203 (5) ◽  
pp. 254-265 ◽  
Author(s):  
Darrin Paul Smith ◽  
Clive Scott Mason ◽  
Elizabeth Jones ◽  
Robert Old
Keyword(s):  
Retinoic Acid ◽  
Partial Resistance ◽  
Retinoic Acid Receptor ◽  
Dominant Negative ◽  
Acid Receptor ◽  
Xenopus Embryos

Retinoic acid-resistant HL-60 cells exclusively contain mutant retinoic acid receptor-alpha

Blood ◽  
1994 ◽  
Vol 83 (11) ◽  
pp. 3298-3302 ◽  
Author(s):  
YP Li ◽  
F Said ◽  
RE Gallagher
Keyword(s):  
Retinoic Acid ◽  
Retinoic Acid Receptor ◽  
Hot Spot ◽  
Dominant Negative ◽  
Reaction Products ◽  
Retinoic Acid Receptor Alpha ◽  
Restriction Endonuclease Site ◽  
Acid Receptor ◽  
Receptor Alpha ◽  
Alpha Gene

Abstract Sequence analysis of the retinoic acid receptor-alpha (RAR alpha) gene from a subline of HL-60 cells (RA-res) stably resistant to all-trans retinoic acid (RA) disclosed a single-base change in codon number 411, the same C to T transition previously reported in an independently selected HL-60 RA resistant clone by Robertson et al (Blood 80:1885, 1992). This mutation eliminates a FokI restriction endonuclease site. Using primers framing this mutation in exon 9 of the RAR alpha gene, we showed that polymerase chain reaction products amplified from either mRNA or genomic DNA templates from the RA-res subline were completely resistant to FokI digestion whereas those from wild-type (wt) HL-60 cells could be digested to completion. The lack of a normal allele in the RA-res cells was confirmed by mixing experiments and hybridization analyses. Southern blot analysis of DNA from the RA-res and wt cells versus control placental DNA indicated that the RAR alpha gene is not haploid. The independent isolation of the same RAR alpha mutation in different laboratories suggests either that the mutation exits in a small subpopulation in the wt line or that this is a mutational “hot spot.” Furthermore, the results indicate that if a dominant negative mode of resistance is involved in the RA-res subline, this must involve interference with the function of heterologous receptor proteins such as the retinoid X receptors. The lack of any normal RAR alpha in this subline may facilitate studies of the mode of action of retinoids.

scholarly journals Novel retinoic acid receptor ligands in Xenopus embryos.

1996 ◽  
Vol 93 (10) ◽  
pp. 4873-4878 ◽  
Author(s):  
B. Blumberg ◽  
J. Bolado ◽  
F. Derguini ◽  
A. G. Craig ◽  
T. A. Moreno ◽  
...  
Keyword(s):  
Retinoic Acid ◽  
Retinoic Acid Receptor ◽  
Receptor Ligands ◽  
Acid Receptor ◽  
Xenopus Embryos

scholarly journals Akt phosphorylates and suppresses the transactivation of retinoic acid receptor α

2006 ◽  
Vol 395 (3) ◽  
pp. 653-662 ◽  
Author(s):  
Harish Srinivas ◽  
Dianren Xia ◽  
Nicole L. Moore ◽  
Ivan P. Uray ◽  
Heetae Kim ◽  
...  
Keyword(s):  
Retinoic Acid ◽  
Retinoic Acid Receptor ◽  
Suppressive Effect ◽  
Dominant Negative ◽  
Nsclc Cell Line ◽  
Acid Receptor ◽  
Growth Inhibitory ◽  
Dominant Negative Form ◽  
Retinoic Acid Receptor Α ◽  
Functional Analyses

The transactivation of nuclear receptors is regulated by both ligand binding and phosphorylation. We previously showed that RARα (retinoic acid receptor α) phosphorylation by c-Jun N-terminal kinase contributes to retinoid resistance in a subset of NSCLC cells (non-small cell lung cancer cells), but the aetiology of this resistance in the remainder has not been fully elucidated [Srinivas, Juroske, Kalyankrishna, Cody, Price, Xu, Narayanan, Weigel and Kurie (2005) Mol. Cell. Biol. 25, 1054–1069]. In the present study, we report that Akt, which is constitutively activated in NSCLC cells, phosphorylates RARα and inhibits its transactivation. Biochemical and functional analyses showed that Akt interacts with RARα and phosphorylates the Ser96 residue of its DNA-binding domain. Mutation of Ser96 to alanine abrogated the suppressive effect of Akt. Overexpression of a dominant-negative form of Akt in an NSCLC cell line decreased RAR phosphorylation, increased RAR transactivation and enhanced the growth-inhibitory effects of an RAR ligand. The findings presented here show that Akt inhibits RAR transactivation and contributes to retinoid resistance in a subset of NSCLC cells.

Sign in / Sign up

Export Citation Format

Share Document