Biology subjects

Yakoub, G.

Publications and source records attributed to Yakoub, G..

2 recordsLinked to original sources

bioRxiv2024

STK19 facilitates the clearance of lesion-stalled RNAPII during transcription-coupled DNA repair

Transcription-coupled DNA repair (TCR) removes bulky DNA lesions impeding RNA polymerase II (RNAPII) transcription. Recent studies have outlined the stepwise assembly of TCR factors CSB, CSA, UVSSA, and TFIIH around lesion-stalled RNAPII. However, the mechanism and factors required for the transition to downstream repair steps, including RNAPII removal to provide repair proteins access to the DNA lesion, remain unclear. Here, we identify STK19 as a new TCR factor facilitating this transition. Loss of STK19 does not impact initial TCR complex assembly or RNAPII ubiquitylation but delays lesion-stalled RNAPII clearance, thereby interfering with the downstream repair reaction. Cryo-EM and mutational analysis reveal that STK19 associates with the TCR complex, positioning itself between RNAPII, UVSSA, and CSA. The structural insights and molecular modeling suggest that STK19 positions the ATPase subunits of TFIIH onto DNA in front of RNAPII. Together, these findings provide new insights into the factors and mechanisms required for TCR.

molecular biology↗

bioRxiv2024

Clearance of DNA damage-arrested RNAPII is selectively impaired in Cockayne syndrome cells

Arrest of elongating RNA polymerase II (RNAPII) at DNA lesions initiates transcription-coupled repair (TCR), involving the concerted action of specific TCR factors, followed by downstream nucleotide excision repair steps. Remarkedly, only congenital defects in the CSA or CSB genes cause the neurodegenerative disorder Cockayne syndrome, which is not observed with other TCR genes, despite their equal importance in TCR. An explanation for this discrepancy has been lacking. In this study, we developed an assay to track the fate of elongating RNAPII at sites of UV-induced DNA lesions. Employing this method on an isogenic collection of TCR knockout cells reveals a selective RNAPII clearance defect in cells defective in CSA or CSB, in contrast to knockouts of other TCR genes. Our findings provide evidence that a deficiency in RNAPII processing and prolonged transcription arrests in response to DNA damage, rather than compromised DNA repair, may underlie the Cockayne syndrome-like neurodegenerative phenotype.

cell biology↗