Click here to close Hello! We notice that you are using Internet Explorer, which is not supported by Xenbase and may cause the site to display incorrectly. We suggest using a current version of Chrome, FireFox, or Safari.
Development 2008 Sep 01;13518:3125-35. doi: 10.1242/dev.022236.
Show Gene links Show Anatomy links

A crucial role for hnRNP K in axon development in Xenopus laevis.

Liu Y , Gervasi C , Szaro BG .

We report that hnRNP K, an RNA-binding protein implicated in multiple aspects of post-transcriptional gene control, is essential for axon outgrowth in Xenopus. Its intracellular localization was found to be consistent with one of its known roles as an mRNA shuttling protein. In early embryos, it was primarily nuclear, whereas later it occupied both the nucleus and cytoplasm to varying degrees in different neuronal subtypes. Antisense hnRNP K morpholino oligonucleotides (MOs) microinjected into blastomeres suppressed hnRNP K expression from neural plate stages through to at least stage 40. Differentiating neural cells in these embryos expressed several markers for terminally differentiated neurons but failed to make axons. Rescue experiments and the use of two separate hnRNP K MOs were carried out to confirm that these effects were specifically caused by knockdown of hnRNP K expression. For insights into the involvement of hnRNP K in neuronal post-transcriptional gene control at the molecular level, we compared effects on expression of the medium neurofilament protein (NF-M), the RNA for which binds hnRNP K, with that of peripherin, another intermediate filament protein, the RNA for which does not bind hnRNP K. hnRNP K knockdown compromised NF-M mRNA nucleocytoplasmic export and translation, but had no effect on peripherin. Because eliminating NF-M from Xenopus axons attenuates, but does not abolish, their outgrowth, hnRNP K must target additional RNAs needed for axon development. Our study supports the idea that translation of at least a subset of RNAs involved in axon development is controlled by post-transcriptional regulatory modules that have hnRNP K as an essential element.

PubMed ID: 18725517
Article link: Development

Species referenced: Xenopus laevis
Genes referenced: b3gat1 b3gat1l hnrnpc hnrnpdl hnrnpk map1a nefm prph sult2a1 tnni3 tubb2b
Antibodies: B3gat1 Ab2 Hnrnpk Ab1 Nefm Ab1 Tubb2b Ab3
Morpholinos: hnrnpk MO1 hnrnpk MO2 pcbp3 MO1

Article Images: [+] show captions