Anti-proliferative protein; the function is mediated by association with deadenylase subunits of the CCR4-NOT complex (PubMed:8632892, PubMed:23236473). Mediates CPEB3-accelerated mRNA deadenylation by binding to CPEB3 and recruiting CNOT7 which leads to target mRNA deadenylation and decay (PubMed:21336257). Interacts with ERBB2 (PubMed:8632892). Interacts with CNOT7 (PubMed:19276069, PubMed:21336257, PubMed:23236473). Interacts with CPEB3 (via C-terminal RNA-binding region); recruits CNOT7 to CPEB3 to form a ternary complex required for mRNA deadenylation and decay (PubMed:21336257). Interacts with CNOT8 (PubMed:23236473). Interacts with CPEB4 (PubMed:21336257). Only a small fraction localizes to the cytoplasm except in late S-phase where more than half of proteins become cytoplasmic. Ubiquitous. Phosphorylated on Ser and Thr residues. Belongs to the BTG family.