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Multicopper oxidase-1 is required for iron homeostasis in Malpighian tubules of Helicoverpa armigera.

Liu X, Sun C, Liu X, Yin X, Wang B, Du M, An S - Sci Rep (2015)

Bottom Line: HaMCO1 was also found to be highly abundant in Malpighian tubules.HaMCO1 knockdown caused a significant decrease in iron accumulation and also significantly reduced transferrin and ferritin transcript expression.Therefore, HaMCO1 is coordinately regulated by 20E and JH and is required for iron homeostasis in Malpighian tubules.

View Article: PubMed Central - PubMed

Affiliation: State key Laboratory of Wheat and Maize Crop Science/College of Plant Protection, Henan Agricultural University, Zhengzhou 450002 P.R. China.

ABSTRACT
Multicopper oxidases (MCOs) are enzymes that contain 10 conserved histidine residues and 1 cysteine residue. MCO1 has been extensively investigated in the midgut because this MCO is implicated in ascorbate oxidation, iron homeostasis and immune responses. However, information regarding the action of MCO1 in Malpighian tubules is limited. In this study, Helicoverpa armigera was used as a model to investigate the function of MCO1 in Malpighian tubules. Sequence analysis results revealed that HaMCO1 exhibits typical MCO characteristics, with 10 histidine and 1 cysteine residues for copper ion binding. HaMCO1 was also found to be highly abundant in Malpighian tubules. Temporal expression patterns indicated that HaMCO1 is mainly expressed during larval molting stages. Hormone treatments [the molting hormone 20-hydroxyecdysone (20E) and juvenile hormone (JH)] revealed that 20E inhibits HaMCO1 transcript expression via its heterodimer receptor, which consists of ecdysone receptor (EcR) and ultraspiracle (USP), and that JH counteracts the action of 20E to activate HaMCO1 transcript expression via its intracellular receptor methoprene-tolerant (Met). HaMCO1 knockdown caused a significant decrease in iron accumulation and also significantly reduced transferrin and ferritin transcript expression. Therefore, HaMCO1 is coordinately regulated by 20E and JH and is required for iron homeostasis in Malpighian tubules.

No MeSH data available.


Regulation by JH of HaMCO1 transcript expression.(A) The effect of JH treatment on the expression of HaMCO1 transcript. (B) qPCR analysis of MET dsRNAi efficiency on the MET transcript level. (C) The effect of MET knockdown on HaMCO1 transcript levels. The 18S rRNA was used as the housekeeping gene for normalization in all qPCR analyses. The data represent the mean ± SD of three biological replicates. The significance of comparisons were determined by Student’s t-test (*p < 0.05, **p < 0.01, ***p < 0.001).
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f7: Regulation by JH of HaMCO1 transcript expression.(A) The effect of JH treatment on the expression of HaMCO1 transcript. (B) qPCR analysis of MET dsRNAi efficiency on the MET transcript level. (C) The effect of MET knockdown on HaMCO1 transcript levels. The 18S rRNA was used as the housekeeping gene for normalization in all qPCR analyses. The data represent the mean ± SD of three biological replicates. The significance of comparisons were determined by Student’s t-test (*p < 0.05, **p < 0.01, ***p < 0.001).

Mentions: Considering that 20E inhibits HaMCO1 transcript expression, we then assessed the role of JH in HaMCO1 transcript expression. The results revealed that JH treatment caused a significant increase in HaMCO1 transcript expression (Fig. 7A), indicating that JH activates HaMCO1 transcript expression. JH also regulated down-stream signals via its intracellular receptor methoprene-tolerant (Met). RNAi-mediated knockdown of Met1 caused a decrease in the HaMCO1 transcript level compared with the EGFP controls (Fig. 7B). After Met1 transcript expression was successfully knocked down by RNAi, JH treatment caused a significant decrease in HaMCO1 transcript levels in Met1 dsRNAi-treated larvae compared with the EGFP controls (Fig. 7C). These results demonstrated that JH promotes HaMCO1 transcript expression via Met1 to attenuate the effect of 20E on HaMCO1 transcript expression.


Multicopper oxidase-1 is required for iron homeostasis in Malpighian tubules of Helicoverpa armigera.

Liu X, Sun C, Liu X, Yin X, Wang B, Du M, An S - Sci Rep (2015)

Regulation by JH of HaMCO1 transcript expression.(A) The effect of JH treatment on the expression of HaMCO1 transcript. (B) qPCR analysis of MET dsRNAi efficiency on the MET transcript level. (C) The effect of MET knockdown on HaMCO1 transcript levels. The 18S rRNA was used as the housekeeping gene for normalization in all qPCR analyses. The data represent the mean ± SD of three biological replicates. The significance of comparisons were determined by Student’s t-test (*p < 0.05, **p < 0.01, ***p < 0.001).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4593997&req=5

f7: Regulation by JH of HaMCO1 transcript expression.(A) The effect of JH treatment on the expression of HaMCO1 transcript. (B) qPCR analysis of MET dsRNAi efficiency on the MET transcript level. (C) The effect of MET knockdown on HaMCO1 transcript levels. The 18S rRNA was used as the housekeeping gene for normalization in all qPCR analyses. The data represent the mean ± SD of three biological replicates. The significance of comparisons were determined by Student’s t-test (*p < 0.05, **p < 0.01, ***p < 0.001).
Mentions: Considering that 20E inhibits HaMCO1 transcript expression, we then assessed the role of JH in HaMCO1 transcript expression. The results revealed that JH treatment caused a significant increase in HaMCO1 transcript expression (Fig. 7A), indicating that JH activates HaMCO1 transcript expression. JH also regulated down-stream signals via its intracellular receptor methoprene-tolerant (Met). RNAi-mediated knockdown of Met1 caused a decrease in the HaMCO1 transcript level compared with the EGFP controls (Fig. 7B). After Met1 transcript expression was successfully knocked down by RNAi, JH treatment caused a significant decrease in HaMCO1 transcript levels in Met1 dsRNAi-treated larvae compared with the EGFP controls (Fig. 7C). These results demonstrated that JH promotes HaMCO1 transcript expression via Met1 to attenuate the effect of 20E on HaMCO1 transcript expression.

Bottom Line: HaMCO1 was also found to be highly abundant in Malpighian tubules.HaMCO1 knockdown caused a significant decrease in iron accumulation and also significantly reduced transferrin and ferritin transcript expression.Therefore, HaMCO1 is coordinately regulated by 20E and JH and is required for iron homeostasis in Malpighian tubules.

View Article: PubMed Central - PubMed

Affiliation: State key Laboratory of Wheat and Maize Crop Science/College of Plant Protection, Henan Agricultural University, Zhengzhou 450002 P.R. China.

ABSTRACT
Multicopper oxidases (MCOs) are enzymes that contain 10 conserved histidine residues and 1 cysteine residue. MCO1 has been extensively investigated in the midgut because this MCO is implicated in ascorbate oxidation, iron homeostasis and immune responses. However, information regarding the action of MCO1 in Malpighian tubules is limited. In this study, Helicoverpa armigera was used as a model to investigate the function of MCO1 in Malpighian tubules. Sequence analysis results revealed that HaMCO1 exhibits typical MCO characteristics, with 10 histidine and 1 cysteine residues for copper ion binding. HaMCO1 was also found to be highly abundant in Malpighian tubules. Temporal expression patterns indicated that HaMCO1 is mainly expressed during larval molting stages. Hormone treatments [the molting hormone 20-hydroxyecdysone (20E) and juvenile hormone (JH)] revealed that 20E inhibits HaMCO1 transcript expression via its heterodimer receptor, which consists of ecdysone receptor (EcR) and ultraspiracle (USP), and that JH counteracts the action of 20E to activate HaMCO1 transcript expression via its intracellular receptor methoprene-tolerant (Met). HaMCO1 knockdown caused a significant decrease in iron accumulation and also significantly reduced transferrin and ferritin transcript expression. Therefore, HaMCO1 is coordinately regulated by 20E and JH and is required for iron homeostasis in Malpighian tubules.

No MeSH data available.