The microtubule-associated protein tumor overexpressed gene binds to the RNA trafficking protein heterogeneous nuclear ribonucleoprotein A2.
In neural cells, such as oligodendrocytes and neurons, transport of certain RNAs along microtubules is mediated by the cis-acting heterogeneous nuclear ribonucleoprotein A2 response element (A2RE) trafficking element and the cognate trans-acting heterogeneous nuclear ribonucleoprotein (hnRNP) A2 trafficking factor. Using a yeast two-hybrid screen, we have identified a microtubule-associated protein, tumor overexpressed gene (TOG)2, as an hnRNP A2 binding partner. The C-terminal third of TOG2 is sufficient for hnRNP A2 binding. TOG2, the large protein isoform of TOG, is the only isoform detected in oligodendrocytes in culture. TOG coimmunoprecipitates with hnRNP A2 present in the cytoskeleton (CSK) fraction of neural cells, and both coprecipitate with microtubule stabilized pellets. Staining with anti-TOG reveals puncta that are localized in proximity to microtubules, often at the plus ends. TOG is colocalized with hnRNP A2 and A2RE-mRNA in trafficking granules that remain associated with CSK-insoluble tissue. These data suggest that TOG mediates the association of hnRNP A2-positive granules with microtubules during transport and/or localization.
Kosturko
Linda D
LD
Department of Neuroscience, University of Connecticut Health Center, Farmington, CT 06030, USA.
Maggipinto
Michael J
MJ
D'Sa
Chrystal
C
Carson
John H
JH
Barbarese
Elisa
E
D000328:Adult; D000818:Animals; D002478:Cells, Cultured; D003599:Cytoskeleton / Q000378:metabolism; D034481:Heterogeneous-Nuclear Ribonucleoprotein Group A-B / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D008297:Male; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism*; D009474:Neurons / Q000378:metabolism; D009836:Oligodendroglia / Q000378:metabolism; D011485:Protein Binding; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D034443:RNA Transport; D051381:Rats; D020798:Two-Hybrid System Techniques
D034481:Heterogeneous-Nuclear Ribonucleoprotein Group A-B; D008869:Microtubule-Associated Proteins; D020033:Protein Isoforms; C439768:hnRNP A2