Isolation of a novel RNA-binding protein and its association with a large ribonucleoprotein particle present in the nucleoplasm of tobacco cells.
A cDNA encoding a protein with a consensus sequence-type RNA-binding domain (CS-RBD) has been isolated from a Nicotiana sylvestris cDNA library. The deduced protein (designated 'RZ-1') contains CS-RBD in its N-terminal half, arginine/aspartic acid repeats in its center and a glycine-rich-C-terminal region in which a zinc finger motif of the CCHC type is present. The corresponding gene appears to be expressed constitutively in all tobacco organs. Immunocytochemical assays revealed that RZ-1 is localized in the nucleoplasm of tobacco cultured cells. Glycerol gradient fractionation of tobacco nuclear lysates showed that RZ-1 is associated with a large ribonucleoprotein particle of around 60 S in size. Nucleic acid-binding assays indicated that RZ-1 binds preferentially to poly (G) and both the CS-RBD and glycine-rich region are necessary for its binding activity. A possible role of RZ-1 is discussed.
Hanano
S
S
Center for Gene Research, Nagoya University, Japan.
Sugita
M
M
Sugiura
M
M
D000595:Amino Acid Sequence; D001483:Base Sequence; D002467:Cell Nucleus / Q000378:metabolism*; D018076:DNA, Complementary; D005990:Glycerol; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D010947:Plants, Toxic; D011068:Poly G / Q000378:metabolism; D011485:Protein Binding; D016601:RNA-Binding Proteins / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D012261:Ribonucleoproteins / Q000378:metabolism*; D014026:Nicotiana / Q000166:cytology / Q000378:metabolism*
D018076:DNA, Complementary; D010940:Plant Proteins; D016601:RNA-Binding Proteins; C100818:RZ-1 protein, Nicotiana sylvestris; D012261:Ribonucleoproteins; D011068:Poly G; D005990:Glycerol