title: Molecular cloning of a human glycophorin B cDNA: nucleotide sequence and genomic relationship to glycophorin A.
abstract: Here we describe the isolation and nucleotide sequence of a human glycophorin B cDNA. The cDNA was identified by differential hybridization of synthetic oligonucleotide probes to a human erythroleukemic cell line (K562) cDNA library constructed in phage vector lambda gt10. The nucleotide sequence of the glycophorin B cDNA was compared with that of a previously cloned glycophorin A cDNA. The nucleotide sequences encoding the NH2-terminal leader peptide and first 26 amino acids of the two proteins are nearly identical. This homologous region is followed by areas specific to either glycophorin A or B and a number of small regions of homology, which in turn are followed by a very homologous region encoding the presumed membrane-spanning portion of the proteins. We used RNA blot hybridization with both cDNA and synthetic oligonucleotide probes to prove our previous hypothesis that glycophorin B is encoded by a single 0.5- to 0.6-kb mRNA and to show that glycophorins A and B are negatively and coordinately regulated by a tumor-promoting phorbol ester, phorbol 12-myristate 13-acetate. We established the intron/exon structure of the glycophorin A and B genes by oligonucleotide mapping; the results suggest a complex evolution of the glycophorin genes.
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D002460:Cell Line; D003001:Cloning, Molecular; D004247:DNA / Q000378:metabolism*; D005796:Genes; D006021:Glycophorins / Q000235:genetics*; D006801:Humans; D007951:Leukemia, Myeloid; D015470:Leukemia, Myeloid, Acute; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D012795:Sialoglycoproteins / Q000235:genetics*
chemical_list: D006021:Glycophorins; D012795:Sialoglycoproteins; D004247:DNA