Cloning and characterization of mouse CCAAT binding factor.
Isolation of cDNA clones for the mouse CCAAT binding factor (mCBF) has revealed the expression of two distinct forms of mCBF that are generated by alternative splicing of a single primary transcript from a gene that maps to chromosome 17. The mCBF1 mRNA encodes a protein of 997 amino acids, whereas the mCBF2 protein is predicted to be only 461 amino acids in length; mCBF1 and human CBF (hCBF) share>80% amino acid sequence identity. Analysis of adult mouse tissue RNAs has revealed that the mCBF1 and mCBF2 mRNAs are ubiquitously expressed, but that mCBF1 mRNA is 5- to 10-fold more abundant than mCBF2 mRNA. Similarly, mCBF mRNA was detected through-out the placenta and in all tissues of the developing embryo from day 8 to day 18 of gestation. Overexpression of the two forms of mCBF in mammalian cells has demonstrated that the mCBF1 and mCBF2 proteins localize to different cellular compartments, with mCBF1 found predominantly in the nucleus and mCBF2 restricted to the cytoplasm. Co-expression of these two forms influences their localization, however, indicating that CBF activity can be regulated by the relative amounts of the two forms expressed in a cell.
Hoeppner
M A
MA
Department of Biochemistry, Northwestern University, Evanston, IL 60208 USA.
Gilbert
D J
DJ
Copeland
N G
NG
Jenkins
N A
NA
Linzer
D I
DI
Wu
B
B
D016475:3T3 Cells; D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D022762:CCAAT-Enhancer-Binding Proteins; D002460:Cell Line; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D017931:DNA Primers / Q000235:genetics; D018076:DNA, Complementary / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism*; D005260:Female; D018507:Gene Expression Regulation, Developmental; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D010920:Placenta / Q000378:metabolism; D011247:Pregnancy; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D014018:Tissue Distribution; D014162:Transfection
D022762:CCAAT-Enhancer-Binding Proteins; D017931:DNA Primers; D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D012333:RNA, Messenger