Anti-RNF8 antibody (ab4183)

Function

E3 ubiquitin-protein ligase required for assembly of repair proteins to sites of DNA damage. Catalyzes the 'Lys-63'-linked ubiquitination of histone H2A and H2AX. Following DNA double-strand breaks (DSBs), it is recruited to the sites of damage by ATM-phosphorylated MDC1, mediates the ubiquitination of histones H2A and H2AX, thereby promoting the formation of TP53BP1 and BRCA1 ionizing radiation-induced foci (IRIF). Promotes the formation of 'Lys-63'-linked polyubiquitin chains and functions with the specific ubiquitin-conjugating UBE2N/UBC13. Substrates that are polyubiquitinated at 'Lys-63' are usually not targeted for degradation. Enforces the G2/M DNA damage checkpoint. Controls the recruitment of UIMC1-BRCC3 (RAP80-BRCC36) and PAXIP1/PTIP to DNA damage sites following DNA double-strand breaks (DSBs). Ubiquitination of histone H2A requires UBE2N but not MMS2 (UBE2V2). May also ubiquitinate histone H2B. Catalyzes the 'Lys-63'-linked ubiquitination of PCNA. May be required for proper exit from mitosis after spindle checkpoint activation and may regulate cytokinesis. May play a role in the regulation of RXRA-mediated transcriptional activity. Not involved in RXRA ubiquitination by UBE2E2.

Tissue specificity

Ubiquitous. In fetal tissues, highest expression in brain, thymus and liver. In adult tissues, highest levels in brain and testis, lowest levels in peripheral blood cells.

Pathway

Protein modification; protein ubiquitination.

Sequence similarities

Belongs to the RNF8 family.
Contains 1 FHA domain.
Contains 1 RING-type zinc finger.

Developmental stage

Low levels at the G1-S boundary increase in intensity during S phase and until the end of the G2 phase. Abruptly decreases in late mitosis (at protein level). Barely detectable in anaphase.

Domain

The FHA domain specifically recognizes and binds ATM-phosphorylated MDC1 and Thr-4827 phosphorylated HERC2.

Post-translational
modifications

Autoubiquitinated through 'Lys-48' and 'Lys-63' of ubiquitin. 'Lys-63' polyubiquitination is mediated by UBE2N. 'Lys-29'-type polyubiquitination is also observed, but it doesn't require its own functional RING-type zinc finger.

Cellular localization

Nucleus. Midbody. Following DNA double-strand breaks, recruited to the sites of damage. During prophase, concomitant with nuclear envelope breakdown, localizes throughout the cell, with a dotted pattern. In telophase, again in the nucleus and also with a discrete dotted pattern in the cytoplasm. In late telophase and during cytokinesis, localizes in the midbody of the tubulin bridge joining the daughter cells. Does not seem to be associated with condensed chromosomes at any time during the cell cycle.

Alternative names

Database links