GPN-loop GTPase 3 (GPN3)

GPN-loop GTPase 3 (GPN3) is a eukaryotic member of the GPN-loop GTPase family, defined by a conserved Gly-Pro-Asn (GPN) motif in the GTPase domain[1][2]. In eukaryotes, three paralogs exist (GPN1, GPN2, GPN3), each playing an essential role in the biogenesis of RNA polymerase II by functioning as assembly chaperones—specifically, they facilitate the assembly and nuclear import of the 12-subunit RNA polymerase II complex[1][2][3]. Depletion or mutation of GPN3 leads to cytoplasmic accumulation of RNA polymerase II subunits and is lethal in yeast and other eukaryotes[1]. GPN-loop GTPases undergo large conformational changes upon GTP hydrolysis, enabling them to bind hydrophobic regions of protein subunits and coordinate their assembly and release[1][2][3]. No therapeutic drugs specifically targeting GPN3 are documented; rather, its critical role in basic cellular processes makes it unlikely to be a selective drug target[1][2][3]. There is no current evidence linking GPN3 directly to specific diseases, but its essential function makes it a fundamental factor in cell biology.

Other names

ATPBD1CAD-009UNQ1876/PRO4319MGC14560ATP-binding domain 1 family member Cprotein x 0004