Cleavage and polyadenylation specificity factor

Definition

Cleavage and polyadenylation specificity factor (CPSF) is a protein complex that plays a crucial role in the processing of pre-mRNA by facilitating the cleavage of the RNA transcript and the addition of a poly(A) tail. This complex ensures that mRNA molecules are properly modified before they are transported from the nucleus to the cytoplasm for translation, impacting gene expression regulation and mRNA stability.

5 Must Know Facts For Your Next Test

1. CPSF recognizes specific RNA sequences at the cleavage site, allowing for precise processing of pre-mRNA.
2. The addition of the poly(A) tail by CPSF is important for mRNA stability and influences the translation efficiency of the mRNA molecule.
3. CPSF interacts with other protein complexes, such as cleavage stimulation factor (CstF), to coordinate the cleavage and polyadenylation processes.
4. Mutations or dysfunction in CPSF can lead to defective mRNA processing, which may result in various diseases or disorders related to gene expression.
5. CPSF is highly conserved across eukaryotic species, highlighting its fundamental role in gene expression regulation.

Review Questions

• What is the role of CPSF in mRNA processing, and how does it ensure accurate modification of pre-mRNA?
  • CPSF plays a pivotal role in mRNA processing by recognizing specific sequences in pre-mRNA and facilitating the cleavage event that allows for polyadenylation. This ensures that mRNA molecules receive a proper 3' end modification, which is crucial for their stability and export from the nucleus. By coordinating with other factors, CPSF helps maintain the integrity of gene expression by producing mature mRNAs ready for translation.
• Discuss how CPSF interacts with other factors during the cleavage and polyadenylation process, and why these interactions are important.
  • CPSF works in conjunction with other protein complexes such as cleavage stimulation factor (CstF) to perform its function during cleavage and polyadenylation. These interactions are vital because they help stabilize the assembly of proteins at the cleavage site, ensuring efficient processing of pre-mRNA. The coordinated action of these factors not only enhances the precision of mRNA modification but also contributes to overall gene expression regulation.
• Evaluate the consequences of impaired CPSF function on gene expression and potential impacts on cellular health.
  • Impaired function of CPSF can lead to incorrect mRNA processing, resulting in unstable or dysfunctional mRNAs. This can disrupt normal gene expression patterns, potentially causing a cascade of cellular issues such as improper protein synthesis or activation of stress responses. The implications can be severe, contributing to various diseases, including cancer or neurodegenerative disorders, underscoring the essential role that CPSF plays in maintaining cellular health through proper mRNA maturation.

Related terms

Polyadenylation: The process of adding a poly(A) tail to the 3' end of an mRNA molecule, which enhances its stability and facilitates export from the nucleus.

Cleavage Factor: Proteins that recognize specific sequences in pre-mRNA and mediate the cleavage event necessary for processing into mature mRNA.

mRNA Processing: The series of modifications that pre-mRNA undergoes to become mature mRNA, including capping, splicing, and polyadenylation.