Sites of phosphorylation of TTP, and their conservation in other members of the ZFP36 family.
(A) Schematic of documented phosphorylations of TTP, based on data from PhosphositePlus [39]. Phosphorylations supported by only one published source are omitted. There may be some bias in the coverage of TTP protein, due to the presence of putative phosphorylation sites in very large or small tryptic fragments, which may be poorly detected. The influence of specific phosphorylations on protein stability may also introduce bias, as discussed in the text. (B) Conservation and divergence of phosphorylation sites in members of the ZFP36 family. TTP, ZFP36L1 and ZFP36L2 proteins are illustrated schematically. Numbers above the N-terminal, zinc finger and C-terminal domains of ZFP36L1 and ZFP36L2 indicate % similarity with TTP itself. Peptide sequences of specific regions are indicated, in each case in the order (from top to bottom) TTP, ZFP36L1 and ZFP36L2. Co-ordinates of specific residues are indicated in the same order. Residues in bold are conserved between TTP and other members of the family. Residues in red are known to be phosphorylated in vivo.