Members of the MAZ family: a novel cDNA clone for MAZ from human pancreatic islet cells.
A human recombinant cDNA clone that encoded a zinc-finger protein (Myc-associated zinc-finger protein of human islet; MAZi) was cloned by screening a cDNA library prepared from human pancreatic islet cells. The encoded protein showed a high degree of homology to the Myc-associated zinc-finger protein MAZ (ZF87 or Pur-1). However, differences between the cDNAs for MAZi and MAZ were found in the length of the encoded polyalanine stretch and in the sequence of the 5'-end leader. MAZi transcripts were significantly more abundant in rat pancreatic islet carcinoma tissue than in normal rat islet cells. Moreover, MAZi protein bound specifically to the pyrimidine-rich strand of the CT-element of the c-myc gene in vitro and strongly induced the expression of chloramphenicol acetyltransferase (CAT) from a c-myc promoter/ CAT reporter construct in human pancreatic cells. Our results suggest that a distinct member of the MAZ family is expressed in human islet cells and enhances the transcriptional activity of the c-myc gene.
Tsutsui
H
H
Department of Molecular Genetics, Beckman Research Institute of the City of Hope, Duarte, California 91010, USA.
Sakatsume
O
O
Itakura
K
K
Yokoyama
K K
KK
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D002478:Cells, Cultured; D015500:Chloramphenicol O-Acetyltransferase / Q000096:biosynthesis; D003001:Cloning, Molecular; D015342:DNA Probes; D018076:DNA, Complementary; D004268:DNA-Binding Proteins / Q000302:isolation & purification / Q000378:metabolism; D017930:Genes, Reporter; D006801:Humans; D007340:Insulinoma; D007515:Islets of Langerhans / Q000378:metabolism*; D008969:Molecular Sequence Data; D010190:Pancreatic Neoplasms; D017433:Protein Structure, Secondary; D051381:Rats; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000302:isolation & purification; D014157:Transcription Factors / Q000096:biosynthesis* / Q000737:chemistry / Q000302:isolation & purification; D016335:Zinc Fingers
D015342:DNA Probes; D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D011994:Recombinant Proteins; D014157:Transcription Factors; C076035:c-MYC-associated zinc finger protein; D015500:Chloramphenicol O-Acetyltransferase