The sea urchin stem-loop-binding protein: a maternally expressed protein that probably functions in expression of multiple classes of histone mRNA.
Following the completion of oogenesis and oocyte maturation, histone mRNAs are synthesized and stored in the sea urchin egg pronucleus. Histone mRNAs are the only mRNAs that are not polyadenylated but instead end in a stem-loop which has been conserved in evolution. The 3' end binds the stem-loop-binding protein (SLBP), and SLBP is required for histone pre-mRNA processing as well as translation of the histone mRNAs. A cDNA encoding a 59 kDa sea urchin SLBP (suSLBP) has been cloned from an oocyte cDNA library. The suSLBP contains an RNA-binding domain that is similar to the RNA-binding domain found in SLBPs from other species, although there is no similarity between the rest of the suSLBP and other SLBPs. The suSLBP is present at constant levels in eggs and for the first 12 h of development. The levels of suSLBP then decline and remain at a low level for the rest of embryogenesis. The suSLBP is concentrated in the egg pronucleus and is released from the nucleus only when cells enter the first mitosis. SuSLBP expressed by in vitro translation does not bind the stem-loop RNA, suggesting that suSLBP is modified to activate RNA binding in sea urchin embryos.
Robertson
Anthony J
AJ
Program in Molecular Biology and Biotechnology, University of North Carolina, Chapel Hill 27599, USA.
Howard
Jason T
JT
Dominski
Zbigniew
Z
Schnackenberg
Bradley J
BJ
Sumerel
Jan L
JL
McCarthy
John J
JJ
Coffman
James A
JA
Marzluff
William F
WF
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002457:Cell Extracts; D002467:Cell Nucleus / Q000378:metabolism; D003001:Cloning, Molecular; D024202:Electrophoretic Mobility Shift Assay; D004625:Embryo, Nonmammalian / Q000196:embryology / Q000378:metabolism; D005260:Female; D005786:Gene Expression Regulation; D018507:Gene Expression Regulation, Developmental; D006657:Histones / Q000235:genetics*; D008938:Mitosis; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D009690:Nucleic Acid Conformation; D010063:Ovum / Q000166:cytology / Q000378:metabolism; D011485:Protein Binding; D012333:RNA, Messenger / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012617:Sea Urchins / Q000196:embryology / Q000235:genetics / Q000378:metabolism*; D039221:mRNA Cleavage and Polyadenylation Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
D002457:Cell Extracts; D006657:Histones; D009687:Nuclear Proteins; D012333:RNA, Messenger; D011994:Recombinant Proteins; D039221:mRNA Cleavage and Polyadenylation Factors