Existence and localization of a protein in zebra finch brain with similar structural features as the large subunit of the splicing factor U2AF.
From brains of the adult male zebra finch, we purified a peptide that has a homologous sequence of the large subunit of human U2AF. U2AF is a non-small-nuclear ribonucleoprotein (snRNP) splicing factor required for pre-spliceosome assembly. U2AF consists of a large and a small subunit, whereas only a large subunit is required for in vitro splicing. To show that U2AF large-subunit-like protein exists in the brain of zebra finches, we conducted immunoblot analysis on brain extract, using antiserum against an isolated peptide with primary structures similar to the U2AF large subunit (ppU2AFls). The immunoblot analysis showed that a protein with a molecular weight of about 60 kd reacted with the anti-ppU2AFls-antibody to a putative peptide of the U2AF large subunit. To examine the localization of this protein in the brain, we also conducted immunohistochemical analysis with the anti-peptide. An intense immunoreaction was restricted within the cellular nucleus throughout the brain, suggesting that this protein may contribute to the pre-spliceosome assembly in almost all of the regions of the brain.
Azumaya
Y
Y
Faculty of Integrated Arts and Sciences, Hiroshima University, Higashi-Hiroshima, Japan.
Kominami
S
S
Tsutsui
K
K
D000595:Amino Acid Sequence; D000818:Animals; D001717:Birds / Q000235:genetics*; D001923:Brain Chemistry; D008969:Molecular Sequence Data; D009687:Nuclear Proteins; D012326:RNA Splicing / Q000235:genetics*; D012261:Ribonucleoproteins / Q000235:genetics* / Q000302:isolation & purification; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity; D000072668:Splicing Factor U2AF; D014018:Tissue Distribution
D009687:Nuclear Proteins; D012261:Ribonucleoproteins; D000072668:Splicing Factor U2AF; C000607494:U2AF2 protein, human