RPF2

RPF2 Full Name

ribosome production factor 2 homolog (S. cerevisiae)

RPF2 Introduction

RPF2 (Ribosome Production Factor 2), also known as BXDC1 (Brix domain-containing protein 1) or ribosome biogenesis protein RPF2 homolog, is an evolutionarily conserved nuclear protein essential for the production of ribosomes. The human gene is located on chromosome 6q21 and encodes a protein that is a key assembly factor for the large (60S) ribosomal subunit. First characterized in yeast as an essential component of the ribosome assembly machinery, RPF2 plays a fundamental role in cellular growth and proliferation by ensuring the correct formation of ribosomes, the molecular machines responsible for protein synthesis.

Figure 1. Strcuture of RPF2.

Structural Domains and Function in Ribosome Assembly and RNA Processing
The RPF2 protein contains a conserved Brix domain, a characteristic feature of proteins involved in ribosome biogenesis that is essential for its function. Additionally, it possesses an RNA-binding domain that allows it to interact with specific RNA molecules, such as the 5S ribosomal RNA and 7S RNA. RPF2 is highly conserved across eukaryotes, with orthologs found in yeast, plants, and all mammals. In yeast, the protein is 344 amino acids long with a molecular weight of approximately 40 kDa, and its complete loss of function is lethal, underscoring its indispensable role in cellular viability. This high degree of evolutionary conservation highlights the fundamental importance of RPF2 in ribosome biology. The primary function of RPF2 is to act as an assembly factor for the large ribosomal subunit. It is part of an early assembly complex that helps to recruit essential components, including the 5S ribosomal RNA and the ribosomal proteins RPL5 and RPL11, to the nascent pre-60S particle. RPF2 functions as a "matchmaker," facilitating the precise folding of ribosomal RNA into its correct three-dimensional structure, a critical step in building a functional ribosome. Beyond this, RPF2 is also involved in the processing of pre‑ribosomal RNA (pre-rRNA), the large precursor molecule that must be cut and trimmed to produce mature rRNA. By coordinating these tasks, RPF2 ensures the efficient and accurate formation of the ribosome's catalytic core.

Cellular Localization and Expression Pattern
To perform its function, RPF2 is primarily localized to the nucleolus, a specialized sub-compartment within the nucleus where ribosome biogenesis takes place. It is also found in the nucleoplasm, and its association with the nucleolus is RNA-dependent. In terms of expression, RPF2 is a ubiquitously expressed protein found in almost all human tissues, which is characteristic of a general cellular "housekeeping" factor. It is consistently expressed at moderate levels across a wide range of organs, including the thyroid, testis, spleen, and bone marrow, reflecting the universal need for ribosome production in all cell types.

Alternate Names for RPF2

RPF2; ribosome production factor 2 homolog (S. cerevisiae); BXDC1; bA397G5.4; ribosome production factor 2 homolog; homolog of Rpf2; brix domain containing 1; brix domain-containing protein 1; ribosomal processing factor 2 homolog; ribosome biogenesis protein RPF2 homolog;