cDNA cloning, expression pattern and RNA binding analysis of human selenocysteine insertion sequence (SECIS) binding protein 2.
Selenocysteine and selenoprotein synthesis require a complex molecular machinery in mammals. Among the key players is the RNA-protein complex formed by the selenocysteine insertion sequence (SECIS) binding protein (SBP2) and the SECIS element, an RNA hairpin in the 3' untranslated regions of selenoprotein messenger RNAs (mRNAs). We have isolated the DNA complementary to mRNA of the human SBP2, enabling us to establish that it differs from a previously reported human SBP2-like protein. Examination of the expression pattern revealed that the human SBP2 protein is encoded by a 4 kb long mRNA that is over-expressed in testis. Compared to the rat SBP2 sequence, the human SBP2 protein displays two highly conserved domains with 92 and 95% amino acid identity, the latter one containing the RNA binding domain. The inter-domain section carries 55% sequence identity, the remainder of the SBP2 sequences showing about 65% identity, values lower than expected for two mammalian proteins. Interestingly, we could show that the binding of human SBP2 to the SECIS RNA is stimulated by the selenoprotein-specialized elongation translation factor mSelB/eEFsec.
Lescure
Alain
A
UPR 9002 du Centre National de la Recherche Scientifique, Institut de Biologie Moléculaire et Cellulaire, 15, Rue René Descartes, 67084 Strasbourg Cedex, France.
Allmang
Christine
C
Yamada
Kenichiro
K
Carbon
Philippe
P
Krol
Alain
A
D000595:Amino Acid Sequence; D015152:Blotting, Northern; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D005260:Female; D015870:Gene Expression; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D010445:Peptide Elongation Factors / Q000378:metabolism; D011485:Protein Binding; D012313:RNA / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid
D018076:DNA, Complementary; D010445:Peptide Elongation Factors; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; C121530:SECISBP2 protein, human; D012313:RNA