Biomaterial Database

The mRNA poly(A)-binding protein: localization, abundance, and RNA-binding specificity. 1994

M Görlach, and C G Burd, and G Dreyfuss

Howard Hughes Medical Institute, University of Pennsylvania School of Medicine, Philadelphia 19104-6148.

The poly(A)-binding protein (PABP) binds to the messenger (mRNA) 3'-poly(A) tail found on most eukaryotic mRNAs and together with the poly(A) tail has been implicated in governing the stability and the translation of mRNA. In order to further understand the role of the PABP in these processes, we have undertaken a detailed analysis of the cellular localization, the abundance, and the RNA-binding properties of the human PABP (hPABP). We raised monoclonal antibodies against the 70-kDa hPABP and confocal immunofluorescence microscopy with these antibodies reveals that it is localized exclusively to the cytoplasm. The hPABP exhibits a very low turnover rate in these cells and quantitative immunoblotting experiments demonstrated that growing HeLa cells contain a surprisingly high number of approximately 8 x 10(6) PABP molecules per cell, which corresponds to an intracellular concentration of about 4 microM. In an in vitro selection/amplification assay from random sequence oligonucleotide pools the hPABP selects oligo(rA)-rich sequences and it binds oligo(rA)25 with an apparent Kd of 7 nM. The hPABP binds to unrelated RNA sequences with an about 100-fold lower affinity (Kd > or = 0.5 microM). The abundance of the hPABP indicates that there is an approximately three-fold excess of the protein over binding sites on cytoplasmic poly(A). This excess and the high concentration of the hPABP, which is three orders of magnitude above its Kd for oligo(rA)25, suggest that the hPABP may bind to additional, lower affinity binding sites in vivo.

UI	MeSH Term	Description	Entries
D007150	Immunohistochemistry	Histochemical localization of immunoreactive substances using labeled antibodies as reagents.	Immunocytochemistry,Immunogold Techniques,Immunogold-Silver Techniques,Immunohistocytochemistry,Immunolabeling Techniques,Immunogold Technics,Immunogold-Silver Technics,Immunolabeling Technics,Immunogold Silver Technics,Immunogold Silver Techniques,Immunogold Technic,Immunogold Technique,Immunogold-Silver Technic,Immunogold-Silver Technique,Immunolabeling Technic,Immunolabeling Technique,Technic, Immunogold,Technic, Immunogold-Silver,Technic, Immunolabeling,Technics, Immunogold,Technics, Immunogold-Silver,Technics, Immunolabeling,Technique, Immunogold,Technique, Immunogold-Silver,Technique, Immunolabeling,Techniques, Immunogold,Techniques, Immunogold-Silver,Techniques, Immunolabeling
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008969	Molecular Sequence Data	Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.	Sequence Data, Molecular,Molecular Sequencing Data,Data, Molecular Sequence,Data, Molecular Sequencing,Sequencing Data, Molecular
D011061	Poly A	A group of adenine ribonucleotides in which the phosphate residues of each adenine ribonucleotide act as bridges in forming diester linkages between the ribose moieties.	Adenine Polynucleotides,Polyadenylic Acids,Poly(rA),Polynucleotides, Adenine
D011993	Recombinant Fusion Proteins	Recombinant proteins produced by the GENETIC TRANSLATION of fused genes formed by the combination of NUCLEIC ACID REGULATORY SEQUENCES of one or more genes with the protein coding sequences of one or more genes.	Fusion Proteins, Recombinant,Recombinant Chimeric Protein,Recombinant Fusion Protein,Recombinant Hybrid Protein,Chimeric Proteins, Recombinant,Hybrid Proteins, Recombinant,Recombinant Chimeric Proteins,Recombinant Hybrid Proteins,Chimeric Protein, Recombinant,Fusion Protein, Recombinant,Hybrid Protein, Recombinant,Protein, Recombinant Chimeric,Protein, Recombinant Fusion,Protein, Recombinant Hybrid,Proteins, Recombinant Chimeric,Proteins, Recombinant Fusion,Proteins, Recombinant Hybrid
D003001	Cloning, Molecular	The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.	Molecular Cloning
D003593	Cytoplasm	The part of a cell that contains the CYTOSOL and small structures excluding the CELL NUCLEUS; MITOCHONDRIA; and large VACUOLES. (Glick, Glossary of Biochemistry and Molecular Biology, 1990)	Protoplasm,Cytoplasms,Protoplasms
D006367	HeLa Cells	The first continuously cultured human malignant CELL LINE, derived from the cervical carcinoma of Henrietta Lacks. These cells are used for, among other things, VIRUS CULTIVATION and PRECLINICAL DRUG EVALUATION assays.	Cell, HeLa,Cells, HeLa,HeLa Cell
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia