RTT103 Antibody

Background and Function of Rtt103

Rtt103 is a transcription termination factor that binds phosphorylated forms of RNA polymerase II (Pol II), specifically interacting with phospho-Ser2 (pSer2) and phospho-Thr4 (pThr4) residues on the C-terminal domain (CTD). This interaction facilitates termination at protein-coding and noncoding genes . Rtt103 also recruits the Rat1-Rai1 exonuclease complex to degrade nascent RNA downstream of poly(A) sites, ensuring proper transcript processing .

Validation of RTT103 Antibody

Key validation data from studies using RTT103-specific antibodies include:

DNA Repair Mechanisms

• Role in DSB Repair: rtt103Δ mutants exhibit hypersensitivity to DNA-damaging agents like methyl methanesulfonate (MMS). Overexpression of RTT103 partially rescues the DNA repair defect in yku70Δ mutants .

• Localization to Damage Sites: Rtt103 associates with chromosomal regions near induced DNA breaks, as shown by ChIP-qPCR .

Transcription Termination

• CTD Phospho-Isoform Binding: Structural studies using NMR demonstrated Rtt103 binds both pSer2 and pThr4 CTD peptides via a conserved arginine residue (R108) .

• Termination at snoRNA Genes: Rtt103 recruitment to snoRNA genes depends on pThr4, with delayed termination observed in T4A mutants .

Telomere and Subtelomeric Regulation

• TERRA Suppression: rtt103Δ mutants show elevated levels of telomeric repeat-containing RNA (TERRA), implicating Rtt103 in degrading subtelomeric transcripts via Rat1 exonuclease recruitment .