CCR4-Not
Carbon Catabolite Repression—Negative On TATA-less, or CCR4-Not, is a multiprotein complex that functions in gene expression. The complex has multiple enzymatic activities as both a poly 3′-5′ exonuclease and a ubiquitin ligase. The complex is present both in the nucleus where it regulates transcription and in the cytoplasm where it associates with translating ribosomes and RNA processing bodies.
Subunits
The human CCR4-Not complex is composed of structural subunits and those that have exonuclease and E3 ligase activity. Some but not all of the human subunits are conserved in budding yeast.| Subunit | MW | Key Features |
| CNOT1 | 267 | "Scaffold" with non-catalytic function. Linked to the maintenance of embryonic stem cells. |
| CNOT2 | 60 | Structural component. Linked to the maintenance of embryonic stem cells. |
| CNOT3 | 82 | Structural component. Linked to the maintenance of embryonic stem cells. |
| CNOT4 | 64 | Active as E3 ubiquitin ligase. |
| CNOT6 | 63 | 3′-5′ exonuclease with preference for polyadenylated mRNA substates. Has a human paralog CNOT6L. |
| CNOT7 | 33 | 3′-5′ exonuclease that is partially redundant with CNOT7. |
| CNOT8 | 34 | 3′-5′ exonuclease. |
| CNOT9 | 34 | Serves a non-catalytic function. |
| CNOT10 | 82 | Non-catalytic subunit that forms a module with CNOT11 that is absent in fungi. |
| CNOT11 | 55 | Non-catalytic subunit that forms a module with CNOT10 that is absent in fungi. |
Molecular weight of human subunits from Uniprot.