CNOT2 (CCR4-NOT transcription complex subunit 2) is a ubiquitous protein encoded by the human gene CNOT2. CNOT2 belongs to the CNOT2/3/5 family and is part of the CCR4-NOT complex. The CCR4-NOT complex is an evolutionarily conserved, multi-component complex known to be involved in transcription as well as mRNA degradation. Various subunits (e.g. CNOT1, CNOT2) are involved in influencing nuclear hormone receptor activities. The CCR4-NOT complex is also involved in the regulation of Histone H3 lysine 4 methylation through a ubiquitin-dependent pathway that likely involves the proteasome. Increased expression of the CNOT2 subunit acts to strongly repress transcription by RNA polymerase II. This repressive effect is mediated by a conserved NOT-Box, which is located at the C-terminus of CNOT2 proteins. Repression by the NOT-Box is sensitive to treatment with the histone deacetylase (HDAC) inhibitor trichostatin A.