Unconventional prefoldin RPB5 interactor 1 (URI1)

Unconventional prefoldin RPB5 interactor 1 (URI1), also known as RMP, is a member of the prefoldin-like chaperone family and a component of the PAQosome complex, which is crucial for the assembly and/or stabilization of various macromolecular complexes in higher eukaryotes[1][4]. URI1 functions as a scaffolding protein and transcriptional regulator, primarily acting as a corepressor by binding to the RNA polymerase II subunit RPB5—modulating transcription and chromatin organization[2][3]. It interacts with other nuclear proteins (e.g., UXT, PDRG1) and is involved in nutrient-dependent mTOR signaling, apoptosis modulation, and maintaining protein homeostasis[1][3]. URI1 plays critical roles in preventing DNA damage, cell survival, cancer progression and suppression, and may act as a feedback regulator for kinase signaling. Although research has highlighted its importance in cancer biology and cell viability, its full molecular functions and potential as a direct therapeutic target are still under investigation[1][3][4].

Other names

URI1Unconventional prefoldin RPB5 interactor 1C19orf2NNX3PPP1R19RMPURIRPB5-mediating proteinFLJ10575Protein phosphatase 1 regulatory subunit 19RNA polymerase II subunit 5-mediating proteinBud27 (yeast ortholog)

Drugs (if developed) would likely act as transcriptional modulators (inhibiting or enhancing repressor function) Antagonism of RPB5 binding (modulates transcriptional repressor complex) Modulation of nutrient-sensing mTOR signaling (indirectly via chaperone complex scaffold) No approved drug mechanisms currently implemented