background:
P55 is an extensively palmitoylated erythrocyte membrane protein, and a member of the MAGUK family. P55 also resists salt extraction, resulting in a high affinity for the plasma membrane. P55 contains a PDZ/DHR domain, a conserved SH-3 domain that appears to suppress tyrosine kinase activity of various oncoproteins, a 39-amino acid motif that binds to cytoskeletal protein 4.1R, and a guanylate kinase-like domain. Interaction with glycophorin C (GPC) and 4.1R suggests that p55 may play a role in the dynamic regulation in the erythrocyte membrane. In addition, p55 gene expression in vivo may be associated with a CpG island. P55 is constitutively expressed in K562 erythroleukemia cells during erythropoiesis and undergoes a 2-fold amplification after induction.
Function:
Component of the CUL4A-RBX1-DDB1-VprBP/DCAF1 E3 ubiquitin-protein ligase complex, VprBP/DCAF1 may function as the substrate recognition module within this complex. For example, VprBP/DCAF1 targets NF2 to the E3 ubiquitin-ligase complex for ubiquitination and subsequent proteasome-dependent degradation. In case of infection by HISLV1 virus, it is recruited by HISLV1 Vpr in order to hijack the CUL4A-RBX1-DDB1 function leading to arrest the cell cycle in G2 phase, and also to protect the viral protein from proteasomal degradation by another E3 ubiquitin ligase. In case of infection by HISLV2 virus, it is recruited by HISLV2 Vpx in order to hijack the CUL4A-RBX1-DDB1 function leading to enhanced efficiency of macrophage infection and promotion of the replication of cognate primate lentiviruses in cells of monocyte/macrophage lineage. Associated with chromatin in a DDB1-independent and cell cycle-dependent manner, VprBP/DCAF1 is recruited to chromatin as DNA is being replicated and is released from chromatin before mitosis.
Subunit:
Component of the CUL4A-RBX1-DDB1-VprBP/DCAF1 E3 ubiquitin-protein ligase complex that could interact with HISLV1 virus Vpr protein and HISLV2 virus Vpx protein. Interacts directly with DDB1. Also forms a ternary complex with DDA1 and DDB1. Interacts with NF2 (via FERM domain). Component of EDD/UBR5-DDB1-VprBP/DCAF1 E3 ubiquitin-protein ligase complex. Associates with the E3 ligase complex containing DYRK2, EDD/UBR5, DDB1 and VPRBP proteins (EDVP complex). Interacts directly with DYRK2.
Subcellular Location:
Cytoplasm. Nucleus.
Tissue Specificity:
Ubiquitously expressed.
Similarity:
Belongs to the VPRBP/DCAF1 family.
Contains 1 LisH domain.
Contains 5 WD repeats.
Database links:
Entrez Gene: 9730 Human
Entrez Gene: 321006 Mouse
Entrez Gene: 315987 Rat
SwissProt: Q9Y4B6 Human
SwissProt: Q80TR8 Mouse
Unigene: 716623 Human
Unigene: 88089 Mouse
Unigene: 32961 Rat
Important Note:
This product as supplied is intended for research use only, not for use in human, therapeutic or diagnostic applications.
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