Cloning of the cDNA of the heme-regulated eukaryotic initiation factor 2 alpha (eIF-2 alpha) kinase of rabbit reticulocytes: homology to yeast GCN2 protein kinase and human double-stranded-RNA-dependent eIF-2 alpha kinase.
We have cloned the cDNA of the heme-regulated eIF-2 alpha kinase (HRI) of rabbit reticulocytes. In vitro translation of mRNA transcribed from the HRI cDNA yields a 90-kDa polypeptide that exhibits eIF-2 alpha kinase activity and is recognized by a monoclonal antibody directed against authentic HRI. The open reading frame sequence of the HRI cDNA contains all 11 catalytic domains of protein kinases with consensus sequences of protein-serine/threonine kinases in conserved catalytic domains VI and VIII. The HRI cDNA also contains an insert of approximately 140 amino acids between catalytic domains V and VI. The HRI cDNA coding sequence has extensive homology to GCN2 protein kinase of Saccharomyces cerevisiae and to human double-stranded-RNA-dependent eIF-2 alpha kinase. This observation suggests that GCN2 protein kinase may be an eIF-2 alpha kinase in yeast. In addition, HRI has an unusually high degree of homology to three protein kinases (NimA, Wee1, and CDC2) that are involved in the regulation of the cell cycle.
Harvard-Massachusetts Institute of Technology Division of Health Sciences and Technology, Cambridge.
J J
JJ
Chen
M S
MS
Throop
L
L
Gehrke
I
I
Kuo
J K
JK
Pal
M
M
Brodsky
I M
IM
London
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D004247:DNA / Q000097:blood / Q000235:genetics* / Q000302:isolation & purification; D006418:Heme / Q000378:metabolism; D006801:Humans; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction / Q000379:methods; D014176:Protein Biosynthesis; D011494:Protein Kinases / Q000235:genetics*; D017346:Protein Serine-Threonine Kinases; D021382:Protein Sorting Signals / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics; D011817:Rabbits; D012156:Reticulocytes / Q000201:enzymology*; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins; D012689:Sequence Homology, Nucleic Acid; D014158:Transcription, Genetic; D019892:eIF-2 Kinase
D021382:Protein Sorting Signals; D012333:RNA, Messenger; D029701:Saccharomyces cerevisiae Proteins; D006418:Heme; D004247:DNA; D011494:Protein Kinases; C512912:GCN2 protein, S cerevisiae; D017346:Protein Serine-Threonine Kinases; D019892:eIF-2 Kinase