Molecular behavior of human Mrt4 protein, MRTO4, in stress conditions is regulated by its C-terminal region.
Protein Mrt4 is one of trans-acting factors involved in ribosome biogenesis, which in higher eukaryotic cells contains a C-terminal extension similar to the C-terminal part of ribosomal P proteins. We show that human Mrt4 (hMrt4/MRTO4) undergoes phosphorylation in vivo and that serines S229, S233, and S235, placed within its acidic C-termini, have been phosphorylated by CK2 kinase in vitro. Such modification does not alter the subcellular distribution of hMrt4 in standard conditions but affects its molecular behavior during ActD induced nucleolar stress. Thus, we propose a new regulatory element important for the stress response pathway connecting ribosome biogenesis with cellular metabolism.
Department of Molecular Biology, Maria Curie-Sklodowska University, Akademicka 19, 20-033 Lublin, Poland.
Barbara
B
Michalec-Wawiorka
Department of Molecular Biology, Maria Curie-Sklodowska University, Akademicka 19, 20-033 Lublin, Poland.
Leszek
L
Wawiorka
Department of Molecular Biology, Maria Curie-Sklodowska University, Akademicka 19, 20-033 Lublin, Poland.
Kamil
K
Derylo
Department of Molecular Biology, Maria Curie-Sklodowska University, Akademicka 19, 20-033 Lublin, Poland.
Dawid
D
Krokowski
Department of Molecular Biology, Maria Curie-Sklodowska University, Akademicka 19, 20-033 Lublin, Poland.
Aleksandra
A
Boguszewska
Department of Molecular Biology, Maria Curie-Sklodowska University, Akademicka 19, 20-033 Lublin, Poland.
Eliza
E
Molestak
Department of Molecular Biology, Maria Curie-Sklodowska University, Akademicka 19, 20-033 Lublin, Poland.
Monika
M
Szajwaj
Department of Molecular Biology, Maria Curie-Sklodowska University, Akademicka 19, 20-033 Lublin, Poland. Electronic address: maro@hektor.umcs.lublin.pl.
Marek
M
Tchorzewski
D000595:Amino Acid Sequence; D047390:Casein Kinase II / Q000737:chemistry; D006367:HeLa Cells; D006801:Humans; D008969:Molecular Sequence Data; D010766:Phosphorylation; D011499:Protein Processing, Post-Translational; D017434:Protein Structure, Tertiary; D021381:Protein Transport; D012269:Ribosomal Proteins / Q000737:chemistry / Q000378:metabolism*; D013312:Stress, Physiological
D047390:Casein Kinase II; D012269:Ribosomal Proteins; C549920:MRTO4 protein, human
Nucleolar stress; Protein phosphorylation; Ribosomal stalk; Ribosome biogenesis; hMrt4/MRTO4 protein