Novel Ribonuclease Activity Differs between Fibrillarins from Arabidopsis thaliana

0486926 - ÚMG 2018 RIV CH eng J - Journal Article
Rodriguez-Corona, U. - Pereira-Santana, A. - Sobol, Margaryta - Rodriguez-Zapata, L.C. - Hozák, Pavel - Castano, E.
Novel Ribonuclease Activity Differs between Fibrillarins from Arabidopsis thaliana.
Frontiers in Plant Science. Roč. 8, podzim (2017), č. článku 1878. ISSN 1664-462X. E-ISSN 1664-462X
R&D Projects: GA ČR GAP305/11/2232; GA ČR(CZ) GA16-03346S; GA ČR GA15-08738S; GA TA ČR(CZ) TE01020118; GA MŠMT(CZ) ED1.1.00/02.0109
Institutional support: RVO:68378050
Keywords : nucleoli * fibrillarin * ribonuclease * phosphoinositides * phosphatidic acid * glycinearginine rich domain
OECD category: Cell biology
Impact factor: 3.677, year: 2017

Fibrillarin is one of the most important nucleolar proteins that have been shown as essential for life. Fibrillarin localizes primarily at the periphery between fibrillar center and dense fibrillar component as well as in Cajal bodies. In most plants there are at least two different genes for fibrillarin. In Arabidopsis thaliana both genes show high level of expression in transcriptionally active cells. Here, we focus on two important differences between A. thaliana fibrillarins. First and most relevant is the enzymatic activity by AtFib2. The AtFib2 shows a novel ribonuclease activity that is not seen with AtFib1. Second is a difference in the ability to interact with phosphoinositides and phosphatidic acid between both proteins. We also show that the novel ribonuclease activity as well as the phospholipid binding region of fibrillarin is confine to the GAR domain. The ribonuclease activity of fibrillarin reveals in this study represents a new role for this protein in rRNA processing.
Permanent Link: http://hdl.handle.net/11104/0281639