Publication Date:
2013-01-20
Description:
The degradation of most eukaryotic mRNAs is initiated by removal of the poly(A) tail, and the major deadenylase activity is associated with the CCR4/CAF1/NOT complex (NOT complex). We here study the role of CNOT10, a protein that is found in human and trypanosome, but not in yeast, NOT complexes. Trypanosome ( Tb ) CNOT10 is essential for growth. Tb CNOT10 interacted with the deadenylase Tb CAF1 and the scaffold protein Tb NOT1; Tb CAF1 also interacted with Tb NOT1 in a yeast two-hybrid assay. In both trypanosomes and human embryonic kidney cells, approximately half of CAF1 was associated with the NOT complex. Depletion of CNOT10 from human cells did not affect this association. In contrast, depletion of Tb CNOT10 in trypanosomes caused a decrease in the level of Tb NOT1, detachment of Tb CAF1 from the complex and pronounced stabilization of most trypanosome mRNAs. Artificial tethering of Tb CAF1 to a reporter mRNA in vivo resulted in mRNA degradation, and this was not affected by Tb CNOT10 depletion. We conclude that in trypanosomes, Tb CNOT10 may stabilize the interaction between Tb CAF1 and the NOT complex. The results further suggest that Tb CAF1 is only able to deadenylate mRNA in vivo if it is recruited to the mRNA through other NOT complex components.
Print ISSN:
0305-1048
Electronic ISSN:
1362-4962
Topics:
Biology
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