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dc.contributor.authorPolitz, Joan C. Ritland
dc.contributor.authorYarovoi, Serge V.
dc.contributor.authorKilroy, Susan M.
dc.contributor.authorGowda, Krishne
dc.contributor.authorZwieb, Christian W.
dc.contributor.authorPederson, Thoru
dc.date2022-08-11T08:09:36.000
dc.date.accessioned2022-08-23T16:37:11Z
dc.date.available2022-08-23T16:37:11Z
dc.date.issued2000-01-05
dc.date.submitted2009-04-02
dc.identifier.citationProc Natl Acad Sci U S A. 2000 Jan 4;97(1):55-60.
dc.identifier.issn0027-8424 (Print)
dc.identifier.pmid10618370
dc.identifier.urihttp://hdl.handle.net/20.500.14038/38958
dc.description.abstractThe signal recognition particle (SRP) is a ribonucleoprotein composed of an Alu domain and an S domain. The S domain contains unique sequence SRP RNA and four SRP proteins: SRP19, SRP54, SRP68, and SRP72. SRP interacts with ribosomes to bring translating membrane and secreted proteins to the endoplasmic reticulum (ER) for proper processing. Additionally, SRP RNA is a member of a family of small nonribosomal RNAs found recently in the nucleolus, suggesting that the nucleolus is more plurifunctional than previously realized. It was therefore of interest to determine whether other SRP components localize to this intranuclear site. In transfected rat fibroblasts, green fluorescent protein fusions of SRP19, SRP68, and SRP72 localized to the nucleolus, as well as to the cytoplasm, as expected. SRP68 also accumulated in the ER, consistent with its affinity for the ER-bound SRP receptor. SRP54 was detected in the cytoplasm as a green fluorescent protein fusion and in immunofluorescence studies, but was not detected in the nucleolus. In situ hybridization experiments also revealed endogenous SRP RNA in the nucleolus. These results demonstrate that SRP RNA and three SRP proteins visit the nucleolus, suggesting that partial SRP assembly, or another unidentified activity of the SRP components, occurs at the nucleolus. SRP54 apparently interacts with nascent SRP beyond the nucleolus, consistent with in vitro reconstitution experiments showing that SRP19 must bind to SRP RNA before SRP54 binds. Our findings support the notion that the nucleolus is the site of assembly and/or interaction between the family of ribonucleoproteins involved in protein synthesis, in addition to ribosomes themselves.
dc.language.isoen_US
dc.relation<a href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&list_uids=10618370&dopt=Abstract">Link to Article in PubMed</a>
dc.relation.urlhttp://www.ncbi.nlm.nih.gov/pmc/articles/PMC26615/?tool=pubmed
dc.subjectAnimals
dc.subjectCell Line
dc.subjectCell Nucleolus
dc.subjectEndoplasmic Reticulum
dc.subjectFluorescent Antibody Technique
dc.subjectGreen Fluorescent Proteins
dc.subjectHumans
dc.subjectIn Situ Hybridization
dc.subjectLuminescent Proteins
dc.subjectMolecular Sequence Data
dc.subjectRNA, Nuclear
dc.subjectRats
dc.subjectRecombinant Fusion Proteins
dc.subject*Saccharomyces cerevisiae Proteins
dc.subjectSignal Recognition Particle
dc.subjectTransfection
dc.subjectLife Sciences
dc.subjectMedicine and Health Sciences
dc.titleSignal recognition particle components in the nucleolus
dc.typeJournal Article
dc.source.journaltitleProceedings of the National Academy of Sciences of the United States of America
dc.source.volume97
dc.source.issue1
dc.identifier.legacycoverpagehttps://escholarship.umassmed.edu/oapubs/1787
dc.identifier.contextkey808553
html.description.abstract<p>The signal recognition particle (SRP) is a ribonucleoprotein composed of an Alu domain and an S domain. The S domain contains unique sequence SRP RNA and four SRP proteins: SRP19, SRP54, SRP68, and SRP72. SRP interacts with ribosomes to bring translating membrane and secreted proteins to the endoplasmic reticulum (ER) for proper processing. Additionally, SRP RNA is a member of a family of small nonribosomal RNAs found recently in the nucleolus, suggesting that the nucleolus is more plurifunctional than previously realized. It was therefore of interest to determine whether other SRP components localize to this intranuclear site. In transfected rat fibroblasts, green fluorescent protein fusions of SRP19, SRP68, and SRP72 localized to the nucleolus, as well as to the cytoplasm, as expected. SRP68 also accumulated in the ER, consistent with its affinity for the ER-bound SRP receptor. SRP54 was detected in the cytoplasm as a green fluorescent protein fusion and in immunofluorescence studies, but was not detected in the nucleolus. In situ hybridization experiments also revealed endogenous SRP RNA in the nucleolus. These results demonstrate that SRP RNA and three SRP proteins visit the nucleolus, suggesting that partial SRP assembly, or another unidentified activity of the SRP components, occurs at the nucleolus. SRP54 apparently interacts with nascent SRP beyond the nucleolus, consistent with in vitro reconstitution experiments showing that SRP19 must bind to SRP RNA before SRP54 binds. Our findings support the notion that the nucleolus is the site of assembly and/or interaction between the family of ribonucleoproteins involved in protein synthesis, in addition to ribosomes themselves.</p>
dc.identifier.submissionpathoapubs/1787
dc.contributor.departmentDepartment of Biochemistry and Molecular Pharmacology
dc.source.pages55-60


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