CNOT8 is a subunit of the CCR4-NOT core complex that contains CCRN4L, CHAF1A, CHAF1B, CNOT1, CNOT2, CNOT3, CNOT4 and CNOT8. The CCR4-NOT complex functions as general transcription regulation complex [].
NOT4, also known as CNOT4 or MOT2, is a component of the CCR4-NOT complex, a global negative regulator of RNA polymerase II transcription []. It associates with polysomes and contributes to the negative regulation of protein synthesis [, , , , , , , ]. NOT4 functions as an E3 ubiquitin-protein ligase that interacts with a specific E2, Ubc4/5 in yeast, and the orthologue UbcH5B in humans, and ubiquitinates a wide range of substrates, including ribosome-associated factors []. Thus, it plays a role in cotranslational quality control (QC) through ribosome-associated ubiquitination and degradation of aberrant peptides. NOT4 contains a C4C4-type RING finger motif, whose overall folding is similar to that of the C3HC4-type RING-HC finger, a central RNA recognition motif (RRM), and a C-terminal domain predicted to be unstructured [].
