English Journal

Where has all the message gone?

Davies E, Stankovic B, Vian A, Wood AJ.Author information Department of Plant Biology, North Carolina State University, Raleigh, NC, USA.AbstractWe provide a brief history of polyribosomes, ergosomes, prosomes, informosomes, maternal mRNA, stored mRNA, and RNP particles. Even though most published research focuses on total mRNA rather than polysomal mRNA and often assumes they are synonymous - i.e., if a functional mRNA is present, it must be translated - results from our laboratories comparing polysomal RNA and total mRNA in a range of "normal" issues show that some transcripts are almost totally absent from polysomes while others are almost entirely associated with polysomes. We describe a recent model from yeast showing various destinies for polysomal mRNA once it has been released from polysomes. The main points we want to emphasize are; a) when mRNA leaves polysomes to go to prosomes, P-bodies, stress granules, etc., it is not necessarily destined for degradation - it can be re-utilized; b) "normal" tissue, not just seeds and stressed tissue, contains functional non-polysomal mRNA; c) association of mRNA with different classes of polysomes affects their sub-cellular location and translatability; and d) drawbacks, misinterpretations, and false hopes arise from analysis of total mRNA rather than polysomal mRNA and from presuming that all polysomes are "created equal".
Plant science : an international journal of experimental plant biology.Plant Sci.2012 Apr;185-186:23-32. doi: 10.1016/j.plantsci.2011.08.001. Epub 2011 Aug 30.
We provide a brief history of polyribosomes, ergosomes, prosomes, informosomes, maternal mRNA, stored mRNA, and RNP particles. Even though most published research focuses on total mRNA rather than polysomal mRNA and often assumes they are synonymous - i.e., if a functional mRNA is present, it must b
PMID 22325863

[mRNPs: from informosomes to stress-granules].

Voronina AS, Pshennikova ES.AbstractEucaryotic cytoplasmic mRNPs named when discovered "informosomes" are intensively investigated now as different mRNP granules. This review contains the data on structure and functioning of these mRNPs. The status of mRNA depends on spectrum of bound proteins and changes by signaling pathways.
Molekuliarnaia biologiia.Mol Biol (Mosk).2010 Jul-Aug;44(4):591-600.
Eucaryotic cytoplasmic mRNPs named when discovered "informosomes" are intensively investigated now as different mRNP granules. This review contains the data on structure and functioning of these mRNPs. The status of mRNA depends on spectrum of bound proteins and changes by signaling pathways.
PMID 20873216

Storage of messenger RNA in eukaryotes: envelopment with protein, translational barrier at 5' side, or conformational masking by 3' side?

Spirin AS.Author information Institute of Protein Research, Russian Academy of Sciences, Pushchino, Moscow Region.AbstractMessenger RNA can be stored in the cytoplasm of higher Eukaryotes in the form of masked messenger ribonucleoprotein particles (masked mRNPs, or informosomes). The typical example is the storage of mRNPs in germ cells (oocytes and spermatocytes). The masked mRNPs are inactive in translation, stable, i.e., protected against degradation, and unavailable for poly(A) tail processing, such as cytoplasmic polyadenylation and deadenylation. The major nonspecific mRNA-binding protein forming mRNPs and belonging to a special p50 family of basic, glycine-rich, phosphorylatable proteins seems to be necessary, but not sufficient for the masking. In some cases, mRNA-specific repressor proteins bound to the 5'-untranslated regions (5'-UTR) of mRNAs may be involved. Interactions of the 3'-untranslated regions (3'-UTR) with sequence-specific proteins seem to be of decisive importance for the masking of mRNPs. The hypothesis is proposed that the masking is achieved through a 3'-UTR-induced conformational rearrangement of mRNP; closing into a circle and condensation of mRNP are considered plausible.
Molecular reproduction and development.Mol Reprod Dev.1994 May;38(1):107-17.
Messenger RNA can be stored in the cytoplasm of higher Eukaryotes in the form of masked messenger ribonucleoprotein particles (masked mRNPs, or informosomes). The typical example is the storage of mRNPs in germ cells (oocytes and spermatocytes). The masked mRNPs are inactive in translation, stable,
PMID 7914085