Fig. 5. ESD1 encodes ARP6. (A) Scheme of the ARP6 gene showing the position of the T-DNA insertion in the esd1-10 mutant. Exons are shown as black boxes. The position of the start and stop codon are indicated. (B) Sequence comparison of AtARP6 with yeast (Sp), C. elegans (Ce), Drosophila (Dm) and human (Hs) ARP6s, and Arabidopsis Actin2. Amino acid residues in black are functionally similar in all sequences and those in gray are similar in at least four of them. Boxed regions indicate the two peptide insertions in ARP6s, which do not disrupt the conserved actin fold structure. GenBank Accession numbers are NP_566861 for AtARP6, AAF4849 for Dm ARP6, AAK14934 for Hs ARP6, CAA19116 for Sp ARP6, NP_495681 for Ce ARP6, and BAB01806 for AtACT2. (C) APR6 expression in different organs of Col plants. RT-PCR assays were performed with RNA prepared from different tissues. R, roots; S, main stems; F, flowers; FB, flower buds; CL, cauline leaves. RT-PCR products were blotted and hybridized with a specific probe for ARP6. UBQ10 was used as a loading control.