caa a22 4500 378849581 CHVBK 20180305123320.0 cr unu---uuuuu 161128e20030127xx s 000 0 eng 10.1515/BC.2003.004 doi (NATIONALLICENCE)gruyter-10.1515/BC.2003.004 Identification and Characterization of ProteinsThat Selectively Interact with Isoforms of themRNA Binding Protein AUF1 (hnRNP D) [Elektronische Daten] [K.C.M. Moraes, A.J.C. Quaresma, K. Maehnss, J. Kobarg] The mRNAs that encode certain cytokines and proto-oncogenes frequently contain a typical AUrich motif that is located in their 3'-untranslated region. The protein AUF1 is the first factor identified that binds to AU rich regions and mediates the fast degradation of the target mRNAs. AUF1 exists as four different isoforms (p37, p40, p42 and p45) that are generated by alternative splicing. The fact that AUF1 does not degrade mRNA itself had led to the suggestion that other AUF1 interacting proteins might be involved in the process of selective mRNA degradation. Here we used the yeast two-hybrid system in order to identify proteins that bind to AUF1. We detected AUF1 itself, as well as the ubiquitin-conjugating enzyme E2I and three RNA binding proteins: NSEP-1, NSAP-1 and IMP-2, as AUF1 interacting proteins. We confirmed all interactions in vitro and mapped the protein domains that are involved in the interaction with AUF1. Gelshift assays with the recombinant purified proteins suggest that the interacting proteins and AUF1 can bind simultaneously to an AU-rich RNA oligonucleotide. Most interestingly, the AUF1 interacting protein NSEP-1showed an endoribonuclease activity in vitro. These data suggest the possibility that the identified AUF1 interacting proteins might be involved in the regulation of mRNA stability mediated by AUF1. Copyright © 2003 by Walter de Gruyter GmbH & Co. KG Biochemistry nationallicence Molecular biology nationallicence Cellular biology nationallicence Moraes K.C.M. aut Quaresma A.J.C. aut Maehnss K. aut Kobarg J. aut Biological Chemistry Walter de Gruyter 384/1(2003-01-27), 25-37 1431-6730 384:1<25 2003 384 bchm https://doi.org/10.1515/BC.2003.004 text/html Onlinezugriff via DOI 1 research article jats NATIONALLICENCE 856 40 https://doi.org/10.1515/BC.2003.004 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Moraes K.C.M. aut NATIONALLICENCE 700 1- Quaresma A.J.C. aut NATIONALLICENCE 700 1- Maehnss K. aut NATIONALLICENCE 700 1- Kobarg J. aut NATIONALLICENCE 773 0- Biological Chemistry Walter de Gruyter 384/1(2003-01-27), 25-37 1431-6730 384:1<25 2003 384 bchm CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-gruyter