Search results for "RNA transport"

Mir-661: A key Factor in Embryo-Maternal dialog With Potential Clinical Application to Predict Implantation Outcome?

2015

Implantation resulting in a full-term pregnancy is, by large, more than a passive process in which the developed conceptus is passively glued to the uterus through adhesive molecules. It is the result of a perfectly orchestrated dialog between a viable embryo and a receptive endometrium, through a mixture of paracrine and juxtacrine processes in which many key proteins and growth factors play fundamental roles (Pellicer et al., 2002.) Since their discovery, microRNAs have become prominent regulatory candidates, providing missing links for a few biological pathways in this process, although their exact role in human normal embryo formation and endometrial preparation for pregnancy remains un…

Proteins from rat liver cytosol which stimulate mRNA transport. Purification and interactions with the nuclear envelope mRNA translocation system.

1986

Two polysome-associated proteins with particular affinities for poly(A) have been purified from rat liver. These proteins stimulate the efflux of mRNA from isolated nuclei in conditions under which such efflux closely stimulates mRNA transport in vivo, and they are therefore considered as mRNA-transport-stimulatory proteins. Their interaction with the mRNA-translocation system in isolated nuclear envelopes has been studied. The results are generally consistent with the most recently proposed kinetic model of mRNA translocation. One protein, P58, has not been described previously. It inhibits the protein kinase that down-regulates the NTPase, it enhances the NTPase activity in both the prese…

Differential effect of insulin and epidermal growth factor on the mRNA translocation system and transport of specific poly(A+) mRNA and poly(A-) mRNA…

1990

The efficiency of efflux of rapidly labeled poly(A)-containing mRNA from isolated rat liver nuclei was found to be modulated by insulin and epidermal growth factor (EGF) in a biphasic but opposite way. At physiological concentrations (10 pM insulin and 1 pM EGF), maximal stimulation of the transport rate by insulin (to 137%) and maximal inhibition by EGF (to 69%) were obtained; at higher concentrations (greater than 100 pM and greater than 10 pM, respectively), the amount of poly(A)-containing mRNA released into the postnuclear supernatant was nearly identical with the level found in untreated nuclei (= 100%). Using mRNA entrapped into closed nuclear envelope (NE) vesicles as a model system…

2013

In the central nervous system (CNS) of most vertebrates, oligodendrocytes enwrap neuronal axons with extensions of their plasma membrane to form the myelin sheath. Several proteins are characteristically found in myelin of which Myelin Basic Protein (MBP) is the second most abundant one after Proteolipid Protein (PLP). The lack of functional MBP in rodents results in a severe hypomyelinated phenotype in the CNS demonstrating its importance for myelin synthesis. Mbp mRNA is transported from the nucleus to the plasma membrane and is translated locally at the axon-glial contact site. Axonal properties such as diameter or electrical activity influence the degree of myelination. As oligodendrocy…

Huntingtin mediates dendritic transport of β-actin mRNA in rat neurons

2011

Transport of mRNAs to diverse neuronal locations via RNA granules serves an important function in regulating protein synthesis within restricted sub-cellular domains. We recently detected the Huntington's disease protein huntingtin (Htt) in dendritic RNA granules; however, the functional significance of this localization is not known. Here we report that Htt and the huntingtin-associated protein 1 (HAP1) are co-localized with the microtubule motor proteins, the KIF5A kinesin and dynein, during dendritic transport of β-actin mRNA. Live cell imaging demonstrated that β-actin mRNA is associated with Htt, HAP1, and dynein intermediate chain in cultured neurons. Reduction in the levels of Htt, H…

Modulation of the nuclear-envelope nucleoside triphosphatase by poly(A)-rich mRNA and by microtubule protein.

1982

Nuclear envelopes contain a nucleoside triphosphatase which is thought to be involved in the supply of energy for nucleo-cytoplasmic RNA transport. This enzyme is stimulated most efficiently by poly(A) and to a lesser extent by poly(G) and poly(dT). Half-maximal stimulation of the enzyme from rat liver nuclei, which was associated with the poly(A)-specific endoribonuclease IV and was free from poly(A) polymerase and endoribonuclease V activity, was determined to occur at a concentration of 1.1 × 106 poly(A) molecules/nuclear ghost. Double-reciprocal plot analyses revealed a 2.8-fold stimulation of the enzyme by poly(A). Poly(A) in the hybrid form had no influence on the activity of the nucl…

A role for Mog1 in H2Bub1 and H3K4me3 regulation affecting RNAPII transcription and mRNA export.

2018

17 páginas, 12 figuras.

Energy requirement and kinetics of transport of poly(A)-free histone mRNA compared to poly(A)-rich mRNA from isolated L-cell nuclei.

1989

ATP-promoted efflux of poly(A)-rich RNA from isolated nuclei of prelabeled mouse lymphoma L5178y cells has an activation energy of 51.5 kJ/mol, similar to that found for the nuclear envelope nucleoside triphosphatase (48.1 kJ/mol) assumed to be involved in mediating nucleocytoplasmic transport of at least some RNA. Here we show that efflux of two specific poly(A)-rich mRNAs (actin and beta-tubulin) from isolated L-cell nuclei is almost totally dependent on the presence of ATP, while efflux of poly(A)-free histone mRNA (H4, H2B, and H1) also occurs to a marked extent in the absence of this nucleotide. Measurements of temperature dependence of transport rate revealed an activation energy of 5…

2015

Oligodendrocytes myelinate neuronal axons in the central nervous system (CNS) facilitating rapid transmission of action potentials by saltatory conduction. Myelin basic protein (MBP) is an essential component of myelin and its absence results in severe hypomyelination in the CNS of rodents. Mbp mRNA is not translated immediately after exit from the nucleus in the cytoplasm, but is transported to the plasma membrane in RNA transport granules in a translationally silenced state. We have previously identified the small non-coding RNA 715 (sncRNA715) as an inhibitor of Mbp translation associated with RNA granules. Argonaute (Ago) proteins and small RNAs form the minimal core of the RNA induced …

A predominantly glial origin of axonal ribosomes after nerve injury

2017

Axonal mRNA transport and local protein synthesis are crucial for peripheral axon regeneration. To date, it remains unclear how ribosomes localize to axons. They may be co-transported with mRNAs or, as suggested by recent studies, transferred from Schwann cells (SC). Here, we generated transgenic "RiboTracker" mice expressing tdTomato-tagged ribosomal protein L4 in specific cell types when crossed with Cre lines. Two neuronal RiboTracker-Cre lines displayed extremely low levels of axonal L4-tdTomato-positive ribosomes. In contrast, two glial RiboTracker-Cre lines revealed tagged ribosomes in sciatic nerve (SN) axons with increasing amounts after injury. Furthermore, non-RiboTracker dorsal r…