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.
Evdokimova
V M
VM
Institute of Protein Research, Russian Academy of Sciences, Puschino, Moscow Region.
Wei
C L
CL
Sitikov
A S
AS
Simonenko
P N
PN
Lazarev
O A
OA
Vasilenko
K S
KS
Ustinov
V A
VA
Hershey
J W
JW
Ovchinnikov
L P
LP
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