The major protein of messenger ribonucleoprotein particles in somatic cells is a member of the Y-box binding transcription factor family.
A cDNA encoding the major core protein, p50, of cytoplasmic messenger ribonucleoprotein particles (mRNPs) of somatic cells was cloned from a rabbit reticulocyte cDNA library. From the derived 324-amino acid sequence, p50 is identified as a member of the Y-box binding transcription factor family. The protein was earlier described as a repressor of globin mRNA translation. These findings suggest that p50 may affect protein biosynthesis at two levels: mRNA transcription in the nucleus and mRNA translation in the cytoplasm. Together with recently published results showing that masked mRNA in germ cells also is associated with proteins of the Y-box binding protein family, the present finding indicates that these proteins are universal core proteins responsible for the formation of cytoplasmic mRNPs in eukaryotes. Highly purified p50 forms large 18 S homomultimeric complexes with a molecular mass of about 800 kilodaltons and melts RNA secondary structure. This suggests that p50 may affect translation by changing the overall structure of the mRNA.
Institute of Protein Research, Russian Academy of Sciences, Puschino, Moscow Region.
V M
VM
Evdokimova
C L
CL
Wei
A S
AS
Sitikov
P N
PN
Simonenko
O A
OA
Lazarev
K S
KS
Vasilenko
V A
VA
Ustinov
J W
JW
Hershey
L P
LP
Ovchinnikov
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D017931:DNA Primers; D015870:Gene Expression; D015723:Gene Library; D005914:Globins / Q000096:biosynthesis*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009838:Oligodeoxyribonucleotides; D016133:Polymerase Chain Reaction; D011132:Polyribosomes / Q000378:metabolism; D012333:RNA, Messenger / Q000096:biosynthesis; D016601:RNA-Binding Proteins; D011817:Rabbits; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000302:isolation & purification; D012097:Repressor Proteins / Q000096:biosynthesis* / Q000737:chemistry; D012156:Reticulocytes / Q000378:metabolism*; D012261:Ribonucleoproteins / Q000096:biosynthesis* / Q000737:chemistry / Q000302:isolation & purification; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors / Q000096:biosynthesis* / Q000737:chemistry; D014158:Transcription, Genetic
D017931:DNA Primers; D009838:Oligodeoxyribonucleotides; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D011994:Recombinant Proteins; D012097:Repressor Proteins; D012261:Ribonucleoproteins; D014157:Transcription Factors; C026452:messenger ribonucleoprotein; C118824:p50 Y-box-binding protein, mammalian; D005914:Globins