PIC 1, a novel ubiquitin-like protein which interacts with the PML component of a multiprotein complex that is disrupted in acute promyelocytic leukaemia.
Acute promyelocytic leukaemia (APL) arises following a reciprocal translocation t(15;17) that fuses PML with retinoic acid receptor alpha (RARA). The PML-RARA fusion protein targets and disrupts nuclear multiprotein complexes called PODs, ND10 or NBs, a process which is associated with a block in myeloid differentiation leading to APL. A human B-cell cDNA library was screened for PML-interacting clones and a single positive clone (PIC1) was isolated. The sequence of PIC1 shows 52% identity to a S. cerevisiae ubiquitin-like protein that was cloned as a suppressor of mutations in MIF2, a protein required for mitotic spindle integrity during anaphase. Transient transfection of NIH3T3 cells with PIC1 results in a nuclear staining pattern coincident with that of endogenous mouse PML. Further, cotransfection of PIC1 with human PML produces a completely overlapping staining pattern between the two proteins. An antibody raised against PIC1 detects a punctate staining pattern in HeLa cells that is coincident with endogenous human PML. There is no significant colocalisation observed between the staining of PML/ PML-RARA and PIC1 in an APL-derived cell line NB4, as compared to cells expressing only wild type PML. However, following all trans retinoic acid treatment of NB4 cells a significant relocalisation of PIC1 and PML is observed. PIC1 is the first identified NB-associated protein that interacts with PML, the function of which may lead to a fuller understanding of the molecular events leading to APL.
Boddy
M N
MN
Protein Structure Laboratory, Imperial Cancer Research Fund, London, UK.
Howe
K
K
Etkin
L D
LD
Solomon
E
E
Freemont
P S
PS
D016475:3T3 Cells; D000595:Amino Acid Sequence; D000818:Animals; D015152:Blotting, Northern; D015153:Blotting, Western; D002460:Cell Line; D002999:Clone Cells; D003001:Cloning, Molecular; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D019084:Fluorescent Antibody Technique, Indirect; D006367:HeLa Cells / Q000378:metabolism; D006801:Humans; D006822:Hybrid Cells; D034882:Lamins; D015473:Leukemia, Promyelocytic, Acute / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D051379:Mice; D008969:Molecular Sequence Data; D009363:Neoplasm Proteins; D009687:Nuclear Proteins / Q000378:metabolism; D000071156:Promyelocytic Leukemia Protein; D014176:Protein Biosynthesis; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D025842:SUMO-1 Protein; D012441:Saccharomyces cerevisiae / Q000235:genetics; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D014018:Tissue Distribution; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014162:Transfection; D014407:Tumor Cells, Cultured; D025521:Tumor Suppressor Proteins; D014452:Ubiquitins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism
C493956:CDKN1A protein, human; C493957:Cdkn1a protein, mouse; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins; D034882:Lamins; D009363:Neoplasm Proteins; D009687:Nuclear Proteins; C513293:Pml protein, mouse; D000071156:Promyelocytic Leukemia Protein; D011993:Recombinant Fusion Proteins; D025842:SUMO-1 Protein; D014157:Transcription Factors; D025521:Tumor Suppressor Proteins; D014452:Ubiquitins; C070576:PML protein, human