Figure 2

Alignment of predicted TaSKs amino acid sequences with selected animal and plant GSKs. TaSK1-A,B,C and TaSK2-A,B,C have been aligned with the Homo sapiens GSK3-β ([GenBank: NP_001139628], major and shorter splice variant), the Drosophila melanogaster SHAGGY isoform H [GenBank: AAS65253] and the Arabidopsis thaliana BIN2 [TAIR: AT4G18710]. Full length protein alignment was performed using ClustalX 2.0.12 software. The catalytic domains of the protein kinases as defined by Hanks and Quinn (1991) [34] are framed in black. The highly conserved motifs CDFGSAK and SYICSR, present only within members of the GSK-3 subfamily of serine/threonine protein kinases are boxed in yellow. The grey box highlights the ATP-binding region. The motif SIDIW present only in members of plant group II GSKs and the animal/human motifs in equivalent position are boxed in green. The blue background highlights the TREE motif of plant GSKs and the motifs present in equivalent position in animal/human GSKs. The MEYV motif that contains key residues for binding of plant GSK inhibitor Bikinin and the corresponding animal motifs are boxed in pink. Arg 96, Arg 180 and Lys205 residues of human GSK-3β defining the pocket for primed substrate binding and being present in equivalent positions in plant GSKs are marked in pink (pink arrowhead). Tyr 216 in human GSK-3β present in equivalent positions in plants and in Drosophila GSKs is marked in green (green arrowhead). Ser 9 present in animal GSKs but absent in TaSKs is highlighted in orange (orange arrowhead).