Rrn6p

Rrn6p is a protein component of the RNA polymerase I transcription machinery in yeast. It is essential for the initiation and elongation of ribosomal RNA (rRNA) transcription, a process critical for cell growth and division. Rrn6p is part of the RNA polymerase I holoenzyme, a complex responsible for transcribing the genes encoding the 18S, 5.8S, and 25S rRNAs. These rRNAs are the building blocks of ribosomes, the cellular factories for protein synthesis.

The function of Rrn6p is closely tied to other subunits of the RNA polymerase I complex, including Rrn7p and Rrn11p. Together, these proteins play a crucial role in the assembly and regulation of the transcription initiation complex at the rDNA promoter. Rrn6p has been shown to interact with the upstream binding factor (UBF) and other general transcription factors, facilitating the recruitment of RNA polymerase I to the rDNA genes.

Studies have revealed that mutations in the gene encoding Rrn6p lead to severe defects in rRNA synthesis and cell growth. This highlights the indispensable role of Rrn6p in maintaining proper ribosome biogenesis and overall cellular homeostasis in yeast. While primarily studied in yeast, the fundamental mechanisms of rRNA transcription are conserved across eukaryotes, suggesting potential functional parallels for Rrn6p homologs in other organisms. Understanding Rrn6p's function provides insights into the intricate regulation of gene expression and the essential process of ribosome production.