Isolation and visualization of large compact ribonucleoprotein particles of specific nuclear RNAs.
We have previously shown that nuclear transcripts of the multifunctional enzyme, carbamoyl-phosphate synthetase, aspartate transcarbamylase, dihydroorotase RNA can be released from nuclei of Syrian hamster cells as compact ribonucleoprotein (RNP) particles that sediment at the 200S region in a sucrose gradient. The 200S nuclear RNP particles contain U1, U2, and U6 small nuclear RNPs, which are known to be required for splicing of pre-mRNA, as integral components of the particles. In this study we demonstrate that nuclear transcripts of dihydrofolate reductase in Syrian hamster cells and of beta-actin in both Syrian hamster and human cells are also released from the respective nuclei as 200S particles--despite the difference in length of these RNAs. Electron microscopy of the 200S particles revealed discrete compact composite structures with a cross section of approximately 50 nm. Finding that two more nuclear RNAs from two different cell types and two different species are released as 200S RNP particles suggests a general mode for packaging of heterogeneous nuclear RNA in large compact RNP particles the size of which is independent of the RNA length.
Spann
P
P
Department of Genetics, Hebrew University of Jerusalem, Israel.
Feinerman
M
M
Sperling
J
J
Sperling
R
R
D000199:Actins / Q000235:genetics / Q000378:metabolism; D000818:Animals; D002460:Cell Line; D002499:Centrifugation, Density Gradient; D006224:Cricetinae; D005347:Fibroblasts; D006367:HeLa Cells; D006801:Humans; D008854:Microscopy, Electron; D009693:Nucleic Acid Hybridization; D015138:RNA, Nuclear / Q000032:analysis*; D012261:Ribonucleoproteins / Q000235:genetics / Q000302:isolation & purification* / Q000648:ultrastructure; D017411:Ribonucleoproteins, Small Nuclear; D013762:Tetrahydrofolate Dehydrogenase / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic
D000199:Actins; D015138:RNA, Nuclear; D012261:Ribonucleoproteins; D017411:Ribonucleoproteins, Small Nuclear; D013762:Tetrahydrofolate Dehydrogenase