ISSN:
1040-452X
Keywords:
Masked mRNA
;
mRNPs
;
mRNA-binding proteins
;
Translational repression
;
mRNA stability
;
mRNA storage in germ cells
;
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
Notes:
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, 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. © 1994 Wiley-Liss, Inc.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/mrd.1080380117
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