Multiple sequence alignment of Arabidopsis caleosin protein sequences. The positions of the motif 6, a calcium-binding motif, a proline knot-like motif, and four phosphorylation sites (one tyrosine kinase and three casein kinase II phosphorylation sites) are indicated on the tops of the sequences. The two invariable proline residues in the proline knot-like motif are labeled by black boxes, two His sites and two Cys sites of dissulfide bridge are highlighted by red and blue frames, respectively. The consensus sequence of the phosphorylation sites are marked by upper lines with the potential phosphorylated residue pointed by arrows. The critical amino acid sites of functional divergence, adaptive selection and coevolution are marked by red triangles, blue circles, and purple stars, respectively.