CBP20 | nuclear cap-binding protein subunit 2

The localization, lack or replacement of the U12 intron in the CBP20 gene does not influence the total level of the CBP20 transcript but impacts the level of CBP20 protein in plants. (A) Real-time qPCR analysis of the total level of the CBP20 transcript in maxi-gene transgenic lines. For each construct, two independent transgenic lines were analyzed. Wt – wild-type plants; cbp20 – cbp20 mutant line; wt transgene – wild-type CBP20 gene structure; U12?U2 – CBP20 gene in which the original U12 intron was replaced with the U2 intron derived from the Arabidopsis CBP80 gene; ?U12 – CBP20 gene with U12 intron deletion; exon swap – the CBP20 gene in which exons no. 4 and no. 5 flanking the U12 intron have been exchanged; U12 in core - a derivative of the U12?U2 construct in which the U12 intron has been introduced between exons no. 3 and no. 4; and U12 in tail - derivative of the U12?U2 construct in which the U12 intron has been introduced between exons no. 5 and no. 6. The CBP20 mRNA level in Wt was taken as 1. Values are shown as the mean ± SD (n = 3) from three independent experiments. (B) Western blot analysis of CBP20 protein levels in transgenic Arabidopsis plants. For each construct, two independent transgenic lines were analyzed. Upper panel – immunoblot using antibodies against CBP20 protein; lower panel – immunoblot with antibodies against actin used as a loading control. Numbers below the western blot image are relative intensities of CBP20 bands calculated using the wt transgene (line 1) CBP20 level as 1. Lines are described as previously.