Figure 3.
Model of TIP41 regulation of PP2As in the ABA signaling pathway. Interaction network between ABA-activated SnRK2-type protein kinases and TOR complex as reported in Wang et al.10 is shown. In presence of ABA, the activated SnRK2s phosphorylate RAPTOR, a component of the TOR complex, to reduce plant growth by inhibiting TOR activity. The TOR kinase phosphorylates TAP46, a regulator of PP2A, which, based on reported phenotypes, may have an opposite function as TIP41.11,25,26 PP2As are composed of three subunits (A, B and C) with a large number of possible dimer or trimer combinations (reported in the figure with different colors) with different cellular functions. TIP41 interacts with and may regulate PP2As affecting different stress responses, based on PP2A subunit combinations. Full arrows indicate established positive (pointed) and negative (barred) protein interactions. Dashed arrows indicate hypothetical regulatory functions.