磷酸化双微体2癌基因重组兔单抗

MDM2

E3 ubiquitin-protein ligase Mdm2

Binds p53/TP53, TP73/p73, ARF/P14, PML, RBL5 and RP11, and specifically to RNA. Can interact with RB1, E1A-associated protein EP300 and the E2F1 transcription factor. Forms a ternary complex with p53/TP53 and WWOX. Interacts with CDKN2AIP, MTBP, RFWD3, TBRG1, USP7, PYHIN1, UBXN6, and RBBP6. Isoform Mdm2-F does not interact with p53/TP53. Interacts with and ubiquitinates HIV-1 Tat. Interacts with ARRB1 and ARRB2. Interacts (isoform 2) with PSMA3. Found in a trimeric complex with MDM2, MDM4 and UPB2. Interacts with USP2 (via N-terminus and C-terminus). Interacts with MDM4. Part of a complex with MDM2, DAXX, RASSF1 and USP7. Part of a complex with DAXX, MDM2 and USP7. Interacts directly with DAXX and USP7. Interacts (via C-terminus) with RASSF1 isoform A (via N-terminus); the interaction is independent of TP53. Interacts with APEX1; leading to its ubiquitination and degradation. Interacts with RYBP; this inhibits ubiquitination of TP53. Identified in a complex with RYBP and p53/TP53. Also component of the TRIM28/KAP1-MDM2-p53/TP53 complex involved in regulating p53/TP53 stabilization and activity. Binds directly both p53/TP53 and TRIM28. Component of the TRIM28/KAP1-ERBB4-MDM2 complex involved in connecting growth factor responses with DNA damage. Interacts directly with both TRIM28 and ERBB4 in the complex. Interacts with DYRK2. Interacts with IGF1R. Interacts with TRIM13; the interaction ubiquitinates MDM2 leading to its proteasomal degradation.

Nucleus, nucleoplasm. Cytoplasm. Nucleus, nucleolus. Expressed predominantly in the nucleoplasm. Interaction with ARF(P14) results in the localization of both proteins to the nucleolus. The nucleolar localization signals in both ARF(P14) and MDM2 may be necessary to allow efficient nucleolar localization of both proteins. Colocalizes with RASSF1 isoform A in the nucleus.

Ubiquitous. Isoform Mdm2-A, isoform Mdm2-B, isoform Mdm2-C, isoform Mdm2-D, isoform Mdm2-E, isoform Mdm2-F and isoform Mdm2-G are observed in a range of cancers but absent in normal tissues.

Phosphorylated in response to ionizing radiation in an ATM-dependent manner.
Auto-ubiquitinated; which leads to proteasomal degradation. Deubiquitinated by USP2 leads to its accumulation and increases deubiquitinilation and degradation of p53/TP53. Deubiquitinated by USP7; leading to stabilize it.

Note=Seems to be amplified in certain tumors (including soft tissue sarcomas, osteosarcomas and gliomas). A higher frequency of splice variants lacking p53 binding domain sequences was found in late-stage and high-grade ovarian and bladder carcinomas. Four of the splice variants show loss of p53 binding.

Belongs to the MDM2/MDM4 family.
Contains 1 RanBP2-type zinc finger.
Contains 1 RING-type zinc finger.
Contains 1 SWIB domain.

E3 ubiquitin-protein ligase that mediates ubiquitination of p53/TP53, leading to its degradation by the proteasome. Inhibits p53/TP53- and p73/TP73-mediated cell cycle arrest and apoptosis by binding its transcriptional activation domain. Also acts as an ubiquitin ligase E3 toward itself and ARRB1. Permits the nuclear export of p53/TP53. Promotes proteasome-dependent ubiquitin-independent degradation of retinoblastoma RB1 protein. Inhibits DAXX-mediated apoptosis by inducing its ubiquitination and degradation. Component of the TRIM28/KAP1-MDM2-p53/TP53 complex involved in stabilizing p53/TP53. Also component of the TRIM28/KAP1-ERBB4-MDM2 complex which links growth factor and DNA damage response pathways.