Involved in the positive regulation of the TOR signaling pathway (PubMed:21216945, PubMed:25399018). Acts as a negative regulator of PP2A catalytic activity (PubMed:10517853, PubMed:21216945, PubMed:24357600). Plays a positive role in the ABA-regulated inhibition of germination, probably throught its interaction with ABI5 (PubMed:24357600). Interacts with the 36 kDa catalytic subunit (subunit C) of PP2A (PubMed:10517853). Interacts with PP2A1 and PP2A2 (PubMed:24357600). Interacts with PP2A3, PPX1 and FYPP1 (PubMed:21216945, PubMed:24357600). Interacts with FYPP3 and ABI5 (PubMed:24357600). Interacts with ATPK1/S6K1 and ATPK2/S6K2 (PubMed:25399018). Interacts with TIP41L (By similarity). Ubiquitous (PubMed:10517853). Highly expressed in seed, and particularly in the embryo (PubMed:24357600). Highly expressed during seed maturation. By chilling (PubMed:10517853). By abscisic acid (ABA) (PubMed:24357600). Phosphorylated by TOR kinase in vitro. RNAi plants show the formation of spontaneous disease-like nectrotic lesions leading to premature cell death. The defective plants also display a strong reduction in protein synthesis, the induction of autophagy and nitrogen mobilization. Plants over-expressing TAP46 exhibit an increased abscisic acid (ABA) sensitivity in seed germination and a reduced PP2A activity (PubMed:24357600). Over-expression of TAP46 also leads to the stimulation of the overall plant growth and the increased nitrogen-assimilating activities (PubMed:25399018). Belongs to the IGBP1/TAP42 family.