Beyond Repair Foci: Subnuclear Domains and the Cellular Response to DNA Damage

SR and SR-related proteins redistribute to segregated fibrillar components of nucleoli in a response to DNA damage

“…Nucleolar segregation is characterized by separation of the nucleolar compartments and the appearance of "nucleolar caps" around the GC, such as those formed by B23. 57,60 Consistent with this fact, we observed separation of the nucleolar compartments by DNA damaging agents such as UV, cisplatin and psoralen. The shape and distribution of d-NAPs and NAPs, however, are likely to be dependent on the distribution of fibrillar components, meaning that they are not always cap-like structures.…”

“…DRB and AMD caused distinct nucleolar disruptions in interphase cells, i.e., "nucleolar fragmentation" and "nucleolar segregation," respectively. 57,60 The nucleolar fragmentation induced by DRB was characterized by the unraveling of fibrillar components and the formation of "nucleolar necklaces," which represent active rDNA transcriptional units (Fig. 4B, j-l and S6, j-l).…”

γH2AX: a sensitive molecular marker of DNA damage and repair

“…61 High numbers of small foci are formed at the early stages of the DDR, decreasing in number and increasing in size as the DDR progresses. 75 If the number of DSBs exceeds the cellular capacity, gH2AX are visualized as diffuse halos rather than distinct foci. 61 ATR-dependent gH2AX phosphorylation as a result of UVC radiation does not present as foci but instead, as a diffuse pattern known as pan-nuclear staining.…”

PDIP38 is translocated to the spliceosomes/nuclear speckles in response to UV-induced DNA damage and is required for UV-induced alternative splicing of MDM2

“…One nuclear compartment subjected to dynamic changes during stress is the promyelocytic leukemia (PML) body. 35 The nucleolus is another nuclear subcompartment that exhibits changes during cellular damage. 36,37 The trafficking of proteins between these compartments and is not recruited to sites of local UV-induced damage.…”