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Heterogeneous Ribonucleic Proteins ( Hnrnps )

Decent Essays

Heterogeneous ribonucleic proteins (HNRNPs) are a family of RNA binding proteins that play a key role in various metabolic functions of RNA. There are roughly twenty major hnRNPs which are readily found in large quantities in the nucleus and in some cases in the cytoplasm. hnRNPs are expressed throughout all tissues at different levels depending on the hnRNP (Kamma et al. 1994). hnRNP metabolic roles include polyadanilation, shuttling mRNA out of the nuclear envelope, telomere biogenesis and localization. (Dreyfuss et al. 2002). In particular, hnRNP A1 can acts an an antagonist to the SF2/ASF protein, which allows A1 to inhibitor exon splicing and cytoplasm bound transport of mRNA. An example of localization is hnRNP A2, which confers the dendritic mRNA transport of various transcripts when induced by neuronal activity (Muslimov et al. 2002).
Role of hnRNP A2/B1
Brain plasticity and learning such as BDNF driven long term synaptic potentiation rely partly on the shuttling and translation of dendritic mRNAs. Large messenger RNA binding proteins such as hnRNP A2/B1 carry inactive dendrite bound mRNA via the microtubule cytoskeleton where they will be translated when they are activated at the synapse (Leal et al. 2014). Brain derived neurotropic factor (BDNF) and increased neuronal activity has shown to regulate the distribution of A2/B1. Particularly an increase in BDNF rises the tendency of cytoplasmic and and dendritic localization. Some key protein transcripts carried by

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