A novel nucleolar protein interacts with ribosomal protein S19.
The gene encoding ribosomal protein S19 (RPS19) is mutated in approximately 25% of patients with Diamond-Blackfan anemia (DBA), which is a rare congenital erythroblastopenia. DBA patients have a variety of clinical characteristics, and the role of the RPS19 gene in the pathogenesis of the disease is presently unknown. To investigate a possible role for RPS19 in erythropoiesis, we looked for proteins associated with mouse RPS19 using a yeast two-hybrid system and identified a novel protein, which we named S19 binding protein (S19BP). The deduced amino acid sequence of S19BP derived from cDNA defines a calculated mass of 15,849 and an isoelectric point of 11.3. No known functional motifs were found in S19BP except a short polylysine tract embedded in a putative nucleolar localization signal. Immunolocalization experiments revealed that S19BP was highly concentrated in nucleoli after 6 h of transfection in Cos-7 cells. S19BP was expressed ubiquitously at a basal level but a significantly high level of expression was observed in some tissues.
Maeda
Noriko
N
Department of Biochemistry, School of Medicine, University of the Ryukyus, 207 Uehara, Nishihara, Okinawa 903-0215, Japan. nmaeda@med.u-ryukyu.ac.jp
Toku
Seikichi
S
Kenmochi
Naoya
N
Tanaka
Tatsuo
T
D000595:Amino Acid Sequence; D000818:Animals; D019556:COS Cells; D002466:Cell Nucleolus / Q000378:metabolism*; D002522:Chlorocebus aethiops; D051379:Mice; D008969:Molecular Sequence Data; D009154:Mutation; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D012269:Ribosomal Proteins / Q000235:genetics / Q000378:metabolism*; D020798:Two-Hybrid System Techniques
D009687:Nuclear Proteins; D012269:Ribosomal Proteins; C507337:S19 binding protein, mouse; C040343:ribosomal protein S19