title: Human ribosomal protein L7 displays an ER binding property and is involved in ribosome-ER association.
abstract: Human ribosomal protein L7 incorporates an ER-binding characteristic. It is evident from the in vivo ER co-localization of the transiently expressed recombinant L7 in mycophenolic acid treated HeLa cells, the in situ detection of the fluorescent L7 at the ER in digitonin-permeablized HeLa cells, and the expression of a similar K(D) value to ribosomes binding to the ER. However, no ER co-localization and a lower K(D) was observed if the last 50 amino acid residues at the carboxyl end of L7 were removed, implying that the carboxyl region embodies the ER-binding specificity. Based on the inhibitory effect of an anti L7 antibody during ribosome rebinding to the microsome, we suggest that the L7-ER-binding nature could be one of multiple factors that allow a nascent peptide-less ribosome to remain at the ER.
authors.affiliation: Institute of Genomic Sciences, National Yang-Ming University, Shih-Pai, Taipei 112, Taiwan, ROC.
authors.forename: Wei-Cheng
authors.initials: WC
authors.lastname: Wu
authors.forename: Houng-Wen
authors.initials: HW
authors.lastname: Liu
authors.forename: Alan
authors.initials: A
authors.lastname: Lin
mesh_terms: D000906:Antibodies / Q000494:pharmacology; D015374:Biosensing Techniques; D002463:Cell Membrane Permeability / Q000187:drug effects; D004721:Endoplasmic Reticulum / Q000187:drug effects / Q000378:metabolism*; D005453:Fluorescence; D006367:HeLa Cells; D006801:Humans; D007700:Kinetics; D008861:Microsomes / Q000187:drug effects / Q000378:metabolism; D050505:Mutant Proteins / Q000378:metabolism; D009173:Mycophenolic Acid / Q000494:pharmacology; D011485:Protein Binding / Q000187:drug effects; D021381:Protein Transport / Q000187:drug effects; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012269:Ribosomal Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism*; D012270:Ribosomes / Q000187:drug effects / Q000378:metabolism*
chemical_list: D000906:Antibodies; D050505:Mutant Proteins; C053634:RPL7 protein, human; D011993:Recombinant Fusion Proteins; D012269:Ribosomal Proteins; D009173:Mycophenolic Acid