Table 1.

Sumoylation targets in the early DDR.

SUMO target	Isoform	Site(s)	E3(s)	Proposed function	Reference
BMI1	SUMO-1	K88	CBX4	Accumulation of BMI1 at DSBs	Ismail et al. (2012)
HERC2	SUMO-1	nd	PIAS4	Promotes binding to RNF8	Danielsen et al. (2012)
RNF168	SUMO-1	nd	PIAS4	Maintain RNF168 levels	Danielsen et al. (2012)
53BP1	SUMO-1	nd	PIAS4	Unknown	Galanty et al. (2009)
BRCA1	SUMO-1, SUMO-2/3	nd	PIAS1, PIAS4	Stimulates ligase activity	Galanty et al. (2009); Morris et al. (2009)
MDC1	SUMO-1, SUMO-2/3	K1840	PIAS4	Signal for RNF4-mediated ubiquitination	Luo et al. (2012)
RAP80	SUMO-1, SUMO-3	nd	nd	unknown	Yan et al. (2007)
RPA70	SUMO-2/3	K449, K577	nd	Facilitates RAD51 recruitment	Dou et al. (2010)

nd, not determined.