RNA polymerase III subunit A (POLR3A)

RNA polymerase III subunit A (POLR3A) is the largest catalytic subunit of the human RNA polymerase III enzyme complex, which is crucial for the transcription of short, non-coding RNAs including all transfer RNAs (tRNAs), 5S ribosomal RNA, and several small nuclear RNAs involved in splicing and regulation[2][3][4][5]. POLR3A forms the catalytic core together with POLR3B and directly orchestrates the enzyme's polymerase activity by recognizing DNA templates and adding ribonucleotides to a growing RNA chain[4][5]. It is also involved in specialized cellular defense mechanisms, notably acting as a cytosolic DNA sensor in innate immune responses and participating in DNA repair[2][4]. Mutations in POLR3A cause distinct genetic syndromes including hypomyelinating leukodystrophy and progeroid syndrome, while dysregulation or enhanced activity is observed in various cancers, making it a potential target for therapeutic intervention, albeit with considerable risk due to its essential and ubiquitous cellular function[1][4][5][6].

Other names

DNA-directed RNA polymerase III subunit RPC1RNA polymerase III subunit C1RPC155RPC1hRPC155C160DNA-directed RNA polymerase III largest subunitRNA polymerase III 155 kDa subunitRNA polymerase III subunit C160ADDHHLD7WDRTSpolymerase (RNA) III (DNA directed) polypeptide A 155 kDapolymerase (RNA) III subunit A

Inhibitors would suppress Pol III transcriptional activity, reducing synthesis of tRNAs and 5S rRNA, thereby affecting protein translation and cellular proliferation—of potential use in cancer therapy