Limits...
AtEAF1 is a potential platform protein for Arabidopsis NuA4 acetyltransferase complex.

Bieluszewski T, Galganski L, Sura W, Bieluszewska A, Abram M, Ludwikow A, Ziolkowski PA, Sadowski J - BMC Plant Biol. (2015)

Bottom Line: Plants carrying a T-DNA insertion in one of the genes encoding AtEAF1 showed decreased FLC expression and early flowering, similarly to Atyaf9 mutants.Chromatin immunoprecipitation analyses of the single mutant Ateaf1b-2 and artificial miRNA knock-down Ateaf1 lines showed decreased levels of H4K5 acetylation in the promoter regions of major flowering regulator genes, further supporting the role of AtEAF1 as a subunit of the plant NuA4 complex.Growing evidence suggests that the molecular functions of the NuA4 and SWR1 complexes are conserved in plants and contribute significantly to plant development and physiology.

View Article: PubMed Central - PubMed

ABSTRACT

Background: Histone acetyltransferase complex NuA4 and histone variant exchanging complex SWR1 are two chromatin modifying complexes which act cooperatively in yeast and share some intriguing structural similarities. Protein subunits of NuA4 and SWR1-C are highly conserved across eukaryotes, but form different multiprotein arrangements. For example, the human TIP60-p400 complex consists of homologues of both yeast NuA4 and SWR1-C subunits, combining subunits necessary for histone acetylation and histone variant exchange. It is currently not known what protein complexes are formed by the plant homologues of NuA4 and SWR1-C subunits.

Results: We report on the identification and molecular characterization of AtEAF1, a new subunit of Arabidopsis NuA4 complex which shows many similarities to the platform protein of the yeast NuA4 complex. AtEAF1 copurifies with Arabidopsis homologues of NuA4 and SWR1-C subunits ARP4 and SWC4 and interacts physically with AtYAF9A and AtYAF9B, homologues of the YAF9 subunit. Plants carrying a T-DNA insertion in one of the genes encoding AtEAF1 showed decreased FLC expression and early flowering, similarly to Atyaf9 mutants. Chromatin immunoprecipitation analyses of the single mutant Ateaf1b-2 and artificial miRNA knock-down Ateaf1 lines showed decreased levels of H4K5 acetylation in the promoter regions of major flowering regulator genes, further supporting the role of AtEAF1 as a subunit of the plant NuA4 complex.

Conclusions: Growing evidence suggests that the molecular functions of the NuA4 and SWR1 complexes are conserved in plants and contribute significantly to plant development and physiology. Our work provides evidence for the existence of a yeast-like EAF1 platform protein in A. thaliana, filling an important gap in the knowledge about the subunit organization of the plant NuA4 complex.

Show MeSH
Plants with transcript levels ofAtEAF1decreased by artificial miRNA show deregulation of flowering time. (a) Expression levels of AtEAF1 in four independent amiRNA lines relative to WT Col-0. (b) Comparison of flowering time represented by an average number of days until the stage where the flower stem is 1 cm long. (c) Comparison of flowering time represented by an average number of true rosette leaves at the stage where the flower stem is 1 cm long. Asterisks in (a, b, c) indicate a p-value < 0.05 or p-value < 0.01 (double asterisk) (t-test).
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
getmorefigures.php?uid=PMC4358907&req=5

Fig5: Plants with transcript levels ofAtEAF1decreased by artificial miRNA show deregulation of flowering time. (a) Expression levels of AtEAF1 in four independent amiRNA lines relative to WT Col-0. (b) Comparison of flowering time represented by an average number of days until the stage where the flower stem is 1 cm long. (c) Comparison of flowering time represented by an average number of true rosette leaves at the stage where the flower stem is 1 cm long. Asterisks in (a, b, c) indicate a p-value < 0.05 or p-value < 0.01 (double asterisk) (t-test).

Mentions: In order to verify if the flowering phenotype of the Ateaf1b-2 mutant is related to the function of AtEAF1, we generated transgenic Arabidopsis plants in which transcript levels of AtEAF1A and AtEAF1B genes were reduced simultaneously through artificial micro RNA (amiRNA) (Figure 5a) [25]. Although independent transgenic lines expressing amiRNA construct displayed a moderate early flowering phenotype (Figure 5b, c), it did not correlate with the decrease in AtEAF1 transcript (Figure 5), In the line 2.39 which showed the earliest flowering we detected only slightly decreased levels of AtEAF1 transcript while line 2.29, with stronger AtEAF1 silencing, showed less obvious early flowering phenotype.Figure 5


AtEAF1 is a potential platform protein for Arabidopsis NuA4 acetyltransferase complex.

Bieluszewski T, Galganski L, Sura W, Bieluszewska A, Abram M, Ludwikow A, Ziolkowski PA, Sadowski J - BMC Plant Biol. (2015)

Plants with transcript levels ofAtEAF1decreased by artificial miRNA show deregulation of flowering time. (a) Expression levels of AtEAF1 in four independent amiRNA lines relative to WT Col-0. (b) Comparison of flowering time represented by an average number of days until the stage where the flower stem is 1 cm long. (c) Comparison of flowering time represented by an average number of true rosette leaves at the stage where the flower stem is 1 cm long. Asterisks in (a, b, c) indicate a p-value < 0.05 or p-value < 0.01 (double asterisk) (t-test).
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4358907&req=5

Fig5: Plants with transcript levels ofAtEAF1decreased by artificial miRNA show deregulation of flowering time. (a) Expression levels of AtEAF1 in four independent amiRNA lines relative to WT Col-0. (b) Comparison of flowering time represented by an average number of days until the stage where the flower stem is 1 cm long. (c) Comparison of flowering time represented by an average number of true rosette leaves at the stage where the flower stem is 1 cm long. Asterisks in (a, b, c) indicate a p-value < 0.05 or p-value < 0.01 (double asterisk) (t-test).
Mentions: In order to verify if the flowering phenotype of the Ateaf1b-2 mutant is related to the function of AtEAF1, we generated transgenic Arabidopsis plants in which transcript levels of AtEAF1A and AtEAF1B genes were reduced simultaneously through artificial micro RNA (amiRNA) (Figure 5a) [25]. Although independent transgenic lines expressing amiRNA construct displayed a moderate early flowering phenotype (Figure 5b, c), it did not correlate with the decrease in AtEAF1 transcript (Figure 5), In the line 2.39 which showed the earliest flowering we detected only slightly decreased levels of AtEAF1 transcript while line 2.29, with stronger AtEAF1 silencing, showed less obvious early flowering phenotype.Figure 5

Bottom Line: Plants carrying a T-DNA insertion in one of the genes encoding AtEAF1 showed decreased FLC expression and early flowering, similarly to Atyaf9 mutants.Chromatin immunoprecipitation analyses of the single mutant Ateaf1b-2 and artificial miRNA knock-down Ateaf1 lines showed decreased levels of H4K5 acetylation in the promoter regions of major flowering regulator genes, further supporting the role of AtEAF1 as a subunit of the plant NuA4 complex.Growing evidence suggests that the molecular functions of the NuA4 and SWR1 complexes are conserved in plants and contribute significantly to plant development and physiology.

View Article: PubMed Central - PubMed

ABSTRACT

Background: Histone acetyltransferase complex NuA4 and histone variant exchanging complex SWR1 are two chromatin modifying complexes which act cooperatively in yeast and share some intriguing structural similarities. Protein subunits of NuA4 and SWR1-C are highly conserved across eukaryotes, but form different multiprotein arrangements. For example, the human TIP60-p400 complex consists of homologues of both yeast NuA4 and SWR1-C subunits, combining subunits necessary for histone acetylation and histone variant exchange. It is currently not known what protein complexes are formed by the plant homologues of NuA4 and SWR1-C subunits.

Results: We report on the identification and molecular characterization of AtEAF1, a new subunit of Arabidopsis NuA4 complex which shows many similarities to the platform protein of the yeast NuA4 complex. AtEAF1 copurifies with Arabidopsis homologues of NuA4 and SWR1-C subunits ARP4 and SWC4 and interacts physically with AtYAF9A and AtYAF9B, homologues of the YAF9 subunit. Plants carrying a T-DNA insertion in one of the genes encoding AtEAF1 showed decreased FLC expression and early flowering, similarly to Atyaf9 mutants. Chromatin immunoprecipitation analyses of the single mutant Ateaf1b-2 and artificial miRNA knock-down Ateaf1 lines showed decreased levels of H4K5 acetylation in the promoter regions of major flowering regulator genes, further supporting the role of AtEAF1 as a subunit of the plant NuA4 complex.

Conclusions: Growing evidence suggests that the molecular functions of the NuA4 and SWR1 complexes are conserved in plants and contribute significantly to plant development and physiology. Our work provides evidence for the existence of a yeast-like EAF1 platform protein in A. thaliana, filling an important gap in the knowledge about the subunit organization of the plant NuA4 complex.

Show MeSH