The function of proteins that interact with mRNA

Abstract

Specific proteins are associated with mRNA in the cytoplasm of eukaryotic cells. The complement of associated proteins depends upon whether the mRNA is an integral component of the polysomal complex being translated, or, alternatively, whether it is part of the non-translated free mRNP fraction. By subjecting cells to ultraviolet irradiation in vivo to cross-link proteins to mRNA, mRNP proteins have been shown to be associated with specific regions of the mRNA molecule. Examination of mRNP complexes containing a unique mRNA has suggested that not all mRNA contain the same family of associated RNA binding proteins. The functions of mRNA associated proteins may include a role in providing stability for mRNA, and/or in modulating translation. With the recent demonstrations that both free and polysomal mRNPs are associated with the cytoskeletal framework, specific mRNP proteins may play a role in determining the subcellular localization of specific mRNPs.

Impaired hepatic apolipoprotein B and E translation in streptozotocin diabetic rats.

“…Proteins, bound by mRNAs, are believed to maintain specific messages in either a translatable or nontranslatable state, and may be important in the association of mRNAs with the cytoskeletal elements of the cell (69). It is of interest that recent studies employing apo B mRNA sequences and rat liver S100 cytosolic extracts indicate that a portion of hepatic apo B mRNA is present in liver as a macromolecular, mRNP complex (70).…”

JIPs and RIPs: the regulation of plant gene expression by jasmonates in response to environmental cues and pathogens.

“…Because these control mRNAs remain translatable in MeJA-treated barley leaf tissue (Reinbothe et al, 1993a(Reinbothe et al, , 1993b, their specific inactivation (e.g., by modifications at their 5' ends) is unlikely. Alternatively, the 5' leader sequences of control and JIP mRNAs might differ structurally, causing control mRNAs to be sequestered (and thus inactivated) in specialized subcellular structures such as messenger ribonucleoprotein particles (Larson and Sells, 1987;Scherrer, 1990).…”

Purification and characterization of the major 50‐kDa repressor protein from cytoplasmic mRNP of rabbit reticulocytes

“…The concentration of LiCl in the mRNP solution was adjusted to 2 M. The preparation was incubated at 0°C for proteins of mRNP, isolated by oligo(dT)-cellulose chromatography using 500 mM NaCl and heparin (step I), (c) proteins not bound to DEAEcellulose (step 3), (d) 175 mM NaCl eluate from DEAE-cellulose (step 3), (e) 500 mM NaCl eluate from DEAE-cellulose (step 3). Molecular masses, in Da, are indicated on the right.…”