The methylation of the C-terminal region of hnRNPQ (NSAP1) is important for its nuclear localization

Journal Article · Fri Jul 28 04:00:00 EDT 2006 · Biochemical and Biophysical Research Communications

DOI:https://doi.org/10.1016/j.bbrc.2006.05.152· OSTI ID:20854381

Passos, Dario O ^[1]; Quaresma, Alexandre J.C. ^[1]; Kobarg, Joerg ^[2]

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1. Centro de Biologia Molecular Estrutural, Laboratorio Nacional de Luz Sincrotron, Rua Giuseppe Maximo Scolfaro 10.000, C.P. 6192, 13084-971 Campinas, SP (Brazil)
2. Centro de Biologia Molecular Estrutural, Laboratorio Nacional de Luz Sincrotron, Rua Giuseppe Maximo Scolfaro 10.000, C.P. 6192, 13084-971 Campinas, SP (Brazil) and Departamento de Bioquimica, Universidade Estadual de Campinas, 13084-970 Campinas, SP (Brazil)

Protein arginine methylation is an irreversible post-translational protein modification catalyzed by a family of at least nine different enzymes entitled PRMTs (protein arginine methyl transferases). Although PRMT1 is responsible for 85% of the protein methylation in human cells, its substrate spectrum has not yet been fully characterized nor are the functional consequences of methylation for the protein substrates well understood. Therefore, we set out to employ the yeast two-hybrid system in order to identify new substrate proteins for human PRMT1. We were able to identify nine different PRMT1 interacting proteins involved in different aspects of RNA metabolism, five of which had been previously described either as substrates for PRMT1 or as functionally associated with PRMT1. Among the four new identified possible protein substrates was hnRNPQ3 (NSAP1), a protein whose function has been implicated in diverse steps of mRNA maturation, including splicing, editing, and degradation. By in vitro methylation assays we were able to show that hnRNPQ3 is a substrate for PRMT1 and that its C-terminal RGG box domain is the sole target for methylation. By further studies with the inhibitor of methylation Adox we provide evidence that hnRNPQ1-3 are methylated in vivo. Finally, we demonstrate by immunofluorescence analysis of HeLa cells that the methylation of hnRNPQ is important for its nuclear localization, since Adox treatment causes its re-distribution from the nucleus to the cytoplasm.

• OSTI ID: 20854381
• Journal Information: Biochemical and Biophysical Research Communications, Journal Name: Biochemical and Biophysical Research Communications Journal Issue: 2 Vol. 346; ISSN 0006-291X; ISSN BBRCA9
• Country of Publication: United States
• Language: English

Related Subjects

60 APPLIED LIFE SCIENCES
ARGININE
CYTOPLASM
HELA CELLS
IN VITRO
IN VIVO
METABOLISM
METHYL TRANSFERASES
METHYLATION
RNA
SPLICING
SUBSTRATES
YEASTS