In vivo half-life of a protein is a function of its amino-terminal residue.

When a chimeric gene encoding a ubiquitin-beta-galactosidase fusion protein is expressed in the yeast Saccharomyces cerevisiae, ubiquitin is cleaved off the nascent fusion protein, yielding a deubiquitinated beta-galactosidase (beta gal). With one exception, this cleavage takes place regardless of the nature of the amino acid residue of beta gal at the ubiquitin-beta gal junction, thereby making it possible to expose different residues at the amino-termini of the otherwise identical beta gal proteins. The beta gal proteins thus designed have strikingly different half-lives in vivo, from more than 20 hours to less than 3 minutes, depending on the nature of the amino acid at the amino-terminus of beta gal. The set of individual amino acids can thus be ordered with respect to the half-lives that they confer on beta gal when present at its amino-terminus (the "N-end rule"). The currently known amino-terminal residues in long-lived, noncompartmentalized intracellular proteins from both prokaryotes and eukaryotes belong exclusively to the stabilizing class as predicted by the N-end rule. The function of the previously described posttranslational addition of single amino acids to protein amino-termini may also be accounted for by the N-end rule. Thus the recognition of an amino-terminal residue in a protein may mediate both the metabolic stability of the protein and the potential for regulation of its stability.

[1]  D. Finley,et al.  Enhancement of immunoblot sensitivity by heating of hydrated filters. , 1986, Analytical biochemistry.

[2]  A. Ciechanover,et al.  Transfer RNA is required for conjugation of ubiquitin to selective substrates of the ubiquitin- and ATP-dependent proteolytic system. , 1986, The Journal of biological chemistry.

[3]  N. Ingoglia,et al.  Protein modification by amino acid addition is increased in crushed sciatic but not optic nerves. , 1986, Science.

[4]  I. Herskowitz,et al.  hflB, a new Escherichia coli locus regulating lysogeny and the level of bacteriophage lambda cII protein. , 1986, Journal of molecular biology.

[5]  E. Melloni,et al.  Extralysosomal protein degradation. , 1986, Annual review of biochemistry.

[6]  H. Bunn,et al.  Amino-terminal processing of proteins: hemoglobin South Florida, a variant with retention of initiator methionine and N alpha-acetylation. , 1985, Proceedings of the National Academy of Sciences of the United States of America.

[7]  A. Varshavsky,et al.  The ubiquitin system: functions and mechanisms , 1985 .

[8]  F Sherman,et al.  Methionine or not methionine at the beginning of a protein , 1985, BioEssays : news and reviews in molecular, cellular and developmental biology.

[9]  A. Goldberg,et al.  Production of abnormal proteins in E. coli stimulates transcription of ion and other heat shock genes , 1985, Cell.

[10]  J. Stewart,et al.  Amino-terminal processing of mutant forms of yeast iso-1-cytochrome c. The specificities of methionine aminopeptidase and acetyltransferase. , 1985, The Journal of biological chemistry.

[11]  A. Goldberg,et al.  The ATP dependence of the degradation of short- and long-lived proteins in growing fibroblasts. , 1985, The Journal of biological chemistry.

[12]  W I Wood,et al.  Base composition-independent hybridization in tetramethylammonium chloride: a method for oligonucleotide screening of highly complex gene libraries. , 1985, Proceedings of the National Academy of Sciences of the United States of America.

[13]  I. A. Rose,et al.  Functional heterogeneity of ubiquitin carrier proteins. , 1985, Progress in clinical and biological research.

[14]  M. Smith,et al.  In vitro mutagenesis. , 1985, Annual review of genetics.

[15]  H. Fritz,et al.  The gapped duplex DNA approach to oligonucleotide-directed mutation construction. , 1984, Nucleic acids research.

[16]  A. Varshavsky,et al.  The yeast ubiquitin gene: head-to-tail repeats encoding a polyubiquitin precursor protein , 1984, Nature.

[17]  E. Dworkin‐Rastl,et al.  Multiple ubiquitin mRNAs during xenopus laevis development contain tandem repeats of the 76 amino acid coding sequence , 1984, Cell.

[18]  A. Berk,et al.  Rapid intracellular turnover of adenovirus 5 early region 1A proteins , 1984, Journal of virology.

[19]  A. Hershko,et al.  Role of the alpha-amino group of protein in ubiquitin-mediated protein breakdown. , 1984, Proceedings of the National Academy of Sciences of the United States of America.

[20]  A. Ciechanover,et al.  Thermolability of ubiquitin-activating enzyme from the mammalian cell cycle mutant ts85 , 1984, Cell.

[21]  A. Ciechanover,et al.  Ubiquitin dependence of selective protein degradation demonstrated in the mammalian cell cycle mutant ts85 , 1984, Cell.

[22]  I. Herskowitz,et al.  Targeting of E. coli β-galactosidase to the nucleus in yeast , 1984, Cell.

[23]  I. Verma,et al.  Viral and cellular fos proteins: A comparative analysis , 1984, Cell.

[24]  C. Deutch.  [18] Aminoacyl-tRNA: Protein transferases , 1984 .

[25]  E. W. Jones.  The synthesis and function of proteases in Saccharomyces: genetic approaches. , 1984, Annual review of genetics.

[26]  Avram Hershko,et al.  Ubiquitin: Roles in protein modification and breakdown , 1983, Cell.

[27]  A. Pardee,et al.  Enhanced synthesis and stabilization of Mr 68,000 protein in transformed BALB/c-3T3 cells: candidate for restriction point control of cell growth. , 1983, Proceedings of the National Academy of Sciences of the United States of America.

[28]  A. Ciechanover,et al.  Components of ubiquitin-protein ligase system. Resolution, affinity purification, and role in protein breakdown. , 1983, The Journal of biological chemistry.

[29]  J M Thornton,et al.  Amino and carboxy-terminal regions in globular proteins. , 1983, Journal of molecular biology.

[30]  R. A. Butow,et al.  How are proteins imported into mitochondria? , 1983, Cell.

[31]  L. Guarente.  Yeast promoters and lacZ fusions designed to study expression of cloned genes in yeast. , 1983, Methods in enzymology.

[32]  H. Echols,et al.  Control of phage λ development by stability and synthesis of cll protein: Role of the viral clll and host hflA, himA and himD genes , 1982, Cell.

[33]  M. Rosenberg,et al.  Purification and properties of a transcriptional activator. The cII protein of phage lambda. , 1982, The Journal of biological chemistry.

[34]  A. Ciechanover,et al.  Mechanisms of intracellular protein breakdown. , 1982, Annual review of biochemistry.

[35]  R. Hough,et al.  The selective degradation of injected proteins occurs principally in the cytosol rather than in lysosomes , 1981, Cell.

[36]  Mark L. Pearson,et al.  Protein degradation in E. coli: The ion mutation and bacteriophage lambda N and cll protein stability , 1981, Cell.

[37]  S. Cohen,et al.  Analysis of gene control signals by DNA fusion and cloning in Escherichia coli. , 1980, Journal of molecular biology.

[38]  G. Blobel,et al.  Intracellular protein topogenesis. , 1980, Proceedings of the National Academy of Sciences of the United States of America.

[39]  F. Sanger,et al.  DNA sequencing with chain-terminating inhibitors. , 1977, Proceedings of the National Academy of Sciences of the United States of America.

[40]  M. Levitt.  A simplified representation of protein conformations for rapid simulation of protein folding. , 1976, Journal of molecular biology.

[41]  U. K. Laemmli,et al.  Cleavage of Structural Proteins during the Assembly of the Head of Bacteriophage T4 , 1970, Nature.

[42]  A. Kaji,et al.  SOLUBLE AMINO ACID-INCORPORATING SYSTEM. I. PREPARATION OF THE SYSTEM AND NATURE OF THE REACTION. , 1965, The Journal of biological chemistry.