Ornithine decarboxylase from Neurospora crassa. Purification, characterization, and regulation by inactivation.

DiGangi, J J; Seyfzadeh, Manouchehr; Davis, Rowland H.

doi:10.1016/s0021-9258(18)47651-x

Cited by 31 publications

(4 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Acidic amino acids outnumber basic amino acids, in keeping with the isoelectric point of the enzyme, pH 5.3 to 5.5 (16). There are 10 cysteines, consistent with the high sulfhydril requirement of the enzyme in vitro (16).…”

Section: T N Y N S V a A H E S S A E D A I E Y S I W G P T C D G I D R I T E S I R Fmentioning

confidence: 76%

“…In N. crassa, ODC is relatively stable in vitro, even in the presence of polyamines (16), and it has a half-life of about 9 h in vivo in polyamine-depleted cells (3). The presence of either free putrescine or free spermidine in cells induces a turnover with a half-life of 55 min (3).…”

Section: Discussionmentioning

confidence: 99%

“…The most conspicuous features of ODC regulation in mammals in response to polyamines are the control of ODC synthesis without a change in ODC mRNA levels and the polyamine-induced increase in the turnover rate of the enzyme (31). In the fungus Neurospora crassa, the regulatory responses of ODC at the level of enzyme protein are the same as in many mammalian systems (3,16). In this study, we describe the sequence of the cloned ODC gene of N. crassa, the nature of its unusual transcript, and a comparison of the deduced primary sequence of ODC with those of other organisms.…”

mentioning

confidence: 99%

“…The other library contained cDNAs of germinating conidia and had at least 84,000 inserts. After being plated, the libraries were screened with antiserum to purified native or denatured ODC protein described previously (16). Nonspecific antibodies were removed by cross-absorption of the antisera with a crude extract of a mutant strain carrying the spe-l nonsense mutation, LV10 (12), and lacking the ODC protein.…”

mentioning

confidence: 99%

See 3 more Smart Citations

Ornithine Decarboxylase Gene of Neurospora crassa: Isolation, Sequence, and Polyamine-Mediated Regulation of Its mRNA

Williams

Barnett

Ristow

et al. 1992

Molecular and Cellular Biology

Self Cite

View full text Add to dashboard Cite

Ornithine decarboxylase (ODC), which initiates the biosynthesis of the polyamines putrescine, spermidine, and spermine, is encoded by the spe-1 gene of the fungus Neurospora crassa. This gene and its cDNA have been cloned and sequenced. The gene has a single 70-nucleotide intron in the coding sequence. The cDNA, comprising the entire coding region, recognizes a single 2.4-kb mRNA in Northern (RNA) blots. The mRNA transcript, defined by S1 mapping, has an extremely long, 535-base leader without strong secondary-structure features or an upstream reading frame. The translational start of the protein is ambiguous: a Met-Val-Met sequence precedes the Pro known to be the N terminus of the ODC polypeptide. The polypeptide encoded by the N. crassa spe-1 gene (484 amino acids) has 46% amino acid identity with that of Saccharomyces cerevisiae (466 amino acids) and 42% with that of mouse (461 amino acids). Alignment of the longer N. crassa sequence with S. cerevisiae and mouse sequences creates gaps in different sites in the S. cerevisiae and mouse sequences, suggesting that N. crassa ODC is closer to an ancestral form of the enzyme than that of either yeast or mouse ODC. N. crassa ODC, which turns over rapidly in vivo in the presence of polyamines, has two PEST sequences, found in most ODCs and other proteins with rapid turnover. In striking contrast to other eucaryotic organisms, the variation in the rate of ODC synthesis in response to polyamines in N. crassa is largely correlated with proportional changes in the abundance of ODC mRNA. Spermidine is the main effector of repression, while putrescine has a weaker effect. However, putrescine accumulation appears to increase the amount of active ODC that is made from a given amount of ODC mRNA, possibly by improving its translatability. Conversely, prolonged starvation for both putrescine and spermidine leads to the differentially impaired translation of ODC mRNA.

show abstract

Section: T N Y N S V a A H E S S A E D A I E Y S I W G P T C D G I D R I T E S I R Fmentioning

confidence: 76%

Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations