The association of prosomes with some of the intermediate filament networks of the animal cell.

Abstract

Abstract. The small RNP complexes of defined morphology

Prosomes discriminate between mRNA of adenovirus‐infected and uninfected HeLa cells

“…Preliminary experiments revealed furthermore that prosomal RNA hybridize very strongly to adenovirus DNA (Dineva, not shown). We assume that the inhibition occurs in an early step of initiation, just before viral mRNAs bind to 40 S subunits, since prosomes were never found associated with polysomes and ribosomal subunits in adenovirus-infected and uninfected HeLa cells ( [19] and Kreutzer, unpublished). Also initiation factors were not directly affected by prosomes, since in vitro translation of viral mRNAs was not recovered with additional lysate (not shown).…”

Interaction between mRNA, ribosomes and the cytoskeleton

“…It is not clear, however, in either of these studies if the Vgl mRNA was present in polysomes or in some untranslated form. Monoclonal antibodies against protein components of prosomes (recently characterized ribonucleoprotein particles which contain untranslated mRNA), stain a fibrous network which coincides with the cytokeratin network in HeLa and PtK cells (Grossi de Sa et al, 1988;Scherrer, 1990). Other large ribonucleoprotein particles called vaults have been reported to be concentrated in actin-rich areas of the cytoplasm (Kedersha & Rome, 1990), but in addition were observed in considerable amounts in the perinuclear region where intermediate filaments are also found, suggesting that they may be associated with the latter cytoskeletal component.…”

“…Thus it appears that certain mRNAs may be either cytoskeletal-bound in polysomes or associated with the cytoskeleton in some untranslated form. In this regard it is interesting to note that recent work has suggested that a class of ribonucleoprotein particles (prosomes) are associated with intermediate filaments (Grossi de Sa et al, 1988).…”

A Novel Role for PA28γ-Proteasome in Nuclear Speckle Organization and SR Protein Trafficking

“…A small percentage, however, seems to be associated with defined cellular structures. In the cytoplasm, the 20S proteasome is found associated with the cytoskeleton (Grossi de Sa et al, 1988), the endoplasmic reticulum (Brooks et al, 2000), and a perinuclear structure that coincides with the centrosome (Wigley et al, 1999). In the nucleus, the 20S proteasome is found in distinct nuclear regions, including PML bodies Wojcik and DeMartino, 2003) and nuclear speckles Rockel et al, 2005).…”