HEED, the Product of the Human Homolog of the Murineeed Gene, Binds to the Matrix Protein of HIV-1
| Autor: | Régis Peytavi, Saw See Hong, Bernard Gay, Arnaud Dupuy d'Angeac, Luc Selig, Serge Bénichou, Richard Benarous, Pierre Boulanger |
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| Rok vydání: | 1999 |
| Předmět: |
Gene isoform
Transcription Genetic HIV Antigens Molecular Sequence Data Gene Products gag Mutagenesis (molecular biology technique) Biopanning Biology Peptide Mapping gag Gene Products Human Immunodeficiency Virus Biochemistry Mice Viral Proteins Animals Humans Amino Acid Sequence Binding site Microscopy Immunoelectron Molecular Biology Gene Gene Library Viral matrix protein Base Sequence cDNA library Polycomb Repressive Complex 2 Intron Cell Biology Blotting Northern Molecular biology Repressor Proteins Microscopy Electron HIV-1 |
| Zdroj: | Journal of Biological Chemistry. 274:1635-1645 |
| ISSN: | 0021-9258 |
| DOI: | 10.1074/jbc.274.3.1635 |
| Popis: | heed, the human homolog of mouse eed and Drosophila esc, two members of the trithorax (trx) and Polycomb group (Pc-G) of genes, was isolated by screening an activated lymphocyte cDNA library versus the immunodeficiency virus type 1 (HIV-1) MA protein used as a bait in a two-hybrid system in yeast. The human EED protein (HEED) had 99. 5% identity with the mouse EED protein and contained seven WD repeats. Two heed gene transcripts were identified, with a putative 407-nucleotide-long intron, giving rise to two HEED protein isoforms of 535 and 494 residues in length, respectively. The shorter HEED isoform, originated from the unspliced message, lacked the seventh WD repeat. HEED was found to bind to MA protein in vitro, as efficiently as in vivo in yeast cells. Site-directed mutagenesis and phage biopanning suggested that the interaction between HEED and MA involved the N-terminal region of the MA protein, including the first polybasic signal, in a MA conformation-dependent manner. In the HEED protein, however, two discrete linear MA-binding motifs were identified within residues 388-403, overlapping the origin of the fifth WD repeat. Deletion of the C-terminal 41 residues of HEED, spanning the seventh WD repeat, as in the 494-residue HEED protein, was detrimental to HEED-MA interaction in vivo, suggesting the existence of another C-terminal binding site and/or a conformational role of the HEED C-terminal domain in the MA-HEED interaction. MA and HEED proteins co-localized within the nucleus of co-transfected human cells and of recombinant baculovirus co-infected insect cells. This and the failure of HEED to bind to uncleaved GAG precursor suggested a role of HEED at the early stages of virus infection, rather than late in the virus life cycle. |
| Databáze: | OpenAIRE |
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