scholarly journals Immunological identification of the alternative oxidase of Neurospora crassa mitochondria.

1989 ◽  
Vol 9 (3) ◽  
pp. 1362-1364 ◽  
Author(s):  
A M Lambowitz ◽  
J R Sabourin ◽  
H Bertrand ◽  
R Nickels ◽  
L McIntosh

Neurospora crassa mitochondria use a branched electron transport system in which one branch is a conventional cytochrome system and the other is an alternative cyanide-resistant, hydroxamic acid-sensitive oxidase that is induced when the cytochrome system is impaired. We used a monoclonal antibody to the alternative oxidase of the higher plant Sauromatum guttatum to identify a similar set of related polypeptides (Mr, 36,500 and 37,000) that was associated with the alternative oxidase activity of N. crassa mitochondria. These polypeptides were not present constitutively in the mitochondria of a wild-type N. crassa strain, but were produced in high amounts under conditions that induced alternative oxidase activity. Under the same conditions, mutants in the aod-1 gene, with one exception, produced apparently inactive alternative oxidase polypeptides, whereas mutants in the aod-2 gene failed to produce these polypeptides. The latter findings support the hypothesis that aod-1 is a structural gene for the alternative oxidase and that the aod-2 gene encodes a component that is required for induction of alternative oxidase activity. Finally, our results indicate that the alternative oxidase is highly conserved, even between plant and fungal species.

1989 ◽  
Vol 9 (3) ◽  
pp. 1362-1364
Author(s):  
A M Lambowitz ◽  
J R Sabourin ◽  
H Bertrand ◽  
R Nickels ◽  
L McIntosh

Neurospora crassa mitochondria use a branched electron transport system in which one branch is a conventional cytochrome system and the other is an alternative cyanide-resistant, hydroxamic acid-sensitive oxidase that is induced when the cytochrome system is impaired. We used a monoclonal antibody to the alternative oxidase of the higher plant Sauromatum guttatum to identify a similar set of related polypeptides (Mr, 36,500 and 37,000) that was associated with the alternative oxidase activity of N. crassa mitochondria. These polypeptides were not present constitutively in the mitochondria of a wild-type N. crassa strain, but were produced in high amounts under conditions that induced alternative oxidase activity. Under the same conditions, mutants in the aod-1 gene, with one exception, produced apparently inactive alternative oxidase polypeptides, whereas mutants in the aod-2 gene failed to produce these polypeptides. The latter findings support the hypothesis that aod-1 is a structural gene for the alternative oxidase and that the aod-2 gene encodes a component that is required for induction of alternative oxidase activity. Finally, our results indicate that the alternative oxidase is highly conserved, even between plant and fungal species.


1981 ◽  
Vol 1 (1) ◽  
pp. 1-8 ◽  
Author(s):  
M L Pall ◽  
J M Trevillyan ◽  
N Hinman

Strains of Neurospora crassa mutant in either of two genes, Crisp-1 (cr1) and Frost (fr), showed no increase of cyclic adenosine 3',5'-monophosphate (cyclic AMP) levels when subjected to several treatments which produce large increases of cyclic AMP in wild-type Neurospora. Evidently, the previously reported deficiencies of adenylate cyclase in these mutants were sufficient to block the normal increases. This fact suggests that both mutants could be used to help determine which control phenomena involve cyclic AMP and to interrupt the control of established cyclic AMP-regulated functions. Earlier studies had suggested an interdependence of the cyclic AMP level and the electric potential difference across the plasma membrane of Neurospora. Present experiments, therefore, employed several strains with the cr1 mutation to test for possible roles of cyclic AMP in recovery and oscillatory behavior of the Neurospora membrane potential. The results showed all such phenomena to be normal in the adenylate cyclase-defective strains, which demonstrates that variations of cyclic AMP are not obligatorily involved in the apparent control processes. Evidence is also presented that the induction of both glucose transport system II and the alternative oxidase do not require elevated cyclic AMP levels.


1980 ◽  
Vol 188 (1) ◽  
pp. 141-144 ◽  
Author(s):  
J Vanderleyden ◽  
C Peeters ◽  
H Verachtert ◽  
H Bertrand

The alternative-oxidase-mediated succinate oxidase activity of Neurospora crassa decreases drastically when mitochondria are fractionated into submitochondrial particles or treated with deoxycholate. The activity, however, can be completely restored in the presence of nucleoside 5′-monophosphates. The purine nucleoside 5′-monophosphates are more effective than the pyrimidine homologues. 5′-GMP gives a 10-fold stimulation of the alternative-oxidase-mediated succinate oxidase activity in submitochondrial particles. A comparison is made with the results obtained earlier with Moniliella tomentosa [Hanssens & Verachtert (1976) J. Bacteriol. 125, 825–835; Vanderleyden, Van Den Eynde & Verachtert (1980) Biochem. J. 186, 309–316].


Genetics ◽  
1996 ◽  
Vol 142 (1) ◽  
pp. 129-140 ◽  
Author(s):  
Qiuhong Li ◽  
R Gary Ritzel ◽  
Lesley L T McLean ◽  
Lee McIntosh ◽  
Tak Ko ◽  
...  

Mitochondria of Neurospora crassa contain a cyanide-resistant alternative respiratory pathway in addition to the cytochrome pathway. The alternative oxidase is present only when electron flow through the cytochrome chain is restricted. Both genomic and cDNA copies for the alternative oxidase gene have been isolated and analyzed. The sequence of the predicted protein is homologous to that of other species. The mRNA for the alternative oxidase is scarce in wild-type cultures grown under normal conditions, but it is abundant in cultures grown in the presence of chloramphenicol, an inhibitor of mitochondrial protein synthesis, or in mutants deficient in mitochondrial cytochromes. Thus, induction of alternative oxidase appears to be at the transcriptional level. Restriction fragment length polymorphism mapping of the isolated gene demonstrated that it is located in a position corresponding to the aod-1 locus. Sequence analysis of mutant aod-1 alleles reveals mutations affecting the coding sequence of the alternative oxidase. The level of aod-1 mRNA in an aod-2 mutant strain that had been grown in the presence of chloramphenicol was reduced several fold relative to wild-type, supporting the hypothesis that the product of aod-2 is required for optimal expression of aod-1.


1987 ◽  
Vol 7 (9) ◽  
pp. 3168-3177
Author(s):  
M G Schechtman

The most distal known gene on Neurospora crassa linkage group VR, his-6, was cloned. A genomic walk resulted in isolation of the telomere at VR. It was obtained from a library in which the endmost nucleotides of the chromosome had not been removed by nuclease treatment before being cloned, and mapping indicates that the entire chromosome end has probably been cloned. Sequences homologous to the terminal 2.5 kilobases of DNA from VR from these Oak Ridge N. crassa strains are found at other sites in the genome. To characterize these sites, I crossed an Oak Ridge-derived his-6 strain with a wild-type strain of different genetic background (Mauriceville) and characterized the hybridization patterns seen in the progeny. It appears that the sequences homologous to the VR terminus are found at genetically different sites in the two parental strains, and no hybridization to the VR telomere from Mauriceville was detected. The other genomic copies identified in the Oak Ridge parent were not telomeres. I suggest that any repeating sequence blocks found immediately adjacent to the VR terminus in Oak Ridge strains must be small and that the repeating element identified in that background may be an N. crassa transposable element integrated near the the chromosome end at VR.


Genetics ◽  
1978 ◽  
Vol 88 (2) ◽  
pp. 255-265
Author(s):  
Jerry F Feldman ◽  
Cheryl A Atkinson

ABSTRACT A circadian clock mutant of Neurospora crassa with a period length of about 25.8 hours (4 hr longer than wild type) has been isolated after mutagenesis of the band strain. This mutant, called frq-5, segregates as a single nuclear gene, maps near the centromere on linkage group III, and is unlinked to four previously described clock mutants clustered on linkage group VII R (Feldman and Hoyle 1973, 1976). frq-5 differs from the other clock mutants in at least two other respects: (1) it is recessive in heterokaryons, and (2) it grows at about 60% the rate of the parent band strain on both minimal and complete media. Double mutants between frq-5 and each of the other clock mutants show additivity of period length-two long period mutants produce a double mutant whose period length is longer than either of the two single mutants, while a long and a short period double mutant has an intermediate period length. Although slow growth and long periodicity of frq-5 have segregated together among more than 300 progeny, slow growth per se is not responsible for the long period, since all the double mutants have the slow growth characteristic of frq-5, but have period lengths both shorter and longer than wild type.


1983 ◽  
Vol 212 (1) ◽  
pp. 205-210 ◽  
Author(s):  
P Maruthi Mohan ◽  
K Sivarama Sastry

Three different Ni2+-resistant strains of Neurospora crassa (NiR1, NiR2 and NiR3) have been isolated. All are stable mutants and are fourfold more resistant to Ni2+ than the parent wild-type strain. NiR1 and NiR2 are also sixfold more resistant to Co2+, whereas NiR3 is only twice as resistant to Co2+; the former two are also twofold more resistant to Zn2+, but NiR3 is not. These three strains also differ in sensitivity to Cu2+. Toxicities and concomitant accumulation patterns of Ni2+, Co2+ and Cu2+ have been examined in these strains. NiR1 and NiR2, despite quantitative individual differences, generally accumulate very high amounts of Ni2+ and Co2+, and Mg2+ reverses the toxicities of these two ions by different mechanisms; Ni2+ uptake is suppressed, but not that of Co2+. In NiR3, Mg2+ controls uptake of both Ni2+ and Co2+. Studies indicate that two kinds of Ni2+-resistant strains of N. crassa exist; one kind is resistant because it can tolerate high intracellular concentrations of heavy-metal ions, whereas the other is resistant because it can control metal-ion accumulation.


1981 ◽  
Vol 1 (1) ◽  
pp. 1-8
Author(s):  
M L Pall ◽  
J M Trevillyan ◽  
N Hinman

Strains of Neurospora crassa mutant in either of two genes, Crisp-1 (cr1) and Frost (fr), showed no increase of cyclic adenosine 3',5'-monophosphate (cyclic AMP) levels when subjected to several treatments which produce large increases of cyclic AMP in wild-type Neurospora. Evidently, the previously reported deficiencies of adenylate cyclase in these mutants were sufficient to block the normal increases. This fact suggests that both mutants could be used to help determine which control phenomena involve cyclic AMP and to interrupt the control of established cyclic AMP-regulated functions. Earlier studies had suggested an interdependence of the cyclic AMP level and the electric potential difference across the plasma membrane of Neurospora. Present experiments, therefore, employed several strains with the cr1 mutation to test for possible roles of cyclic AMP in recovery and oscillatory behavior of the Neurospora membrane potential. The results showed all such phenomena to be normal in the adenylate cyclase-defective strains, which demonstrates that variations of cyclic AMP are not obligatorily involved in the apparent control processes. Evidence is also presented that the induction of both glucose transport system II and the alternative oxidase do not require elevated cyclic AMP levels.


1985 ◽  
Vol 5 (12) ◽  
pp. 3593-3599
Author(s):  
V B Patel ◽  
N H Giles

In Neurospora crassa, the qa-1F regulatory gene positively controls transcription of all genes in the quinic acid (qa) gene cluster. qa-1F is transcribed at a low, uninduced level but is subject to strong (50-fold), autogenous regulation as well as to control by the negative regulatory gene, qa-1S, and the inducer quinic acid. Cloned qa-1F DNA sequences hybridize to two related mRNAs of 2.9 and 3.0 kilobases. When wild-type (qa-1F+) cultures are transferred to inducing conditions, qa-1F mRNA increases for 4 h, remains somewhat level, and decreases after 8 to 10 h. That this control is autogenous, i.e., that the qa-1F gene controls the synthesis of its own mRNA, is indicated by the presence of approximately the same low level of qa-1F mRNA in poly(A)+ RNA from noninducible qa-1F- mutant cultures under inducing conditions as that observed in uninduced wild-type cultures. The qa-1S gene also regulates the transcription of qa-1F, since a qa-1S- mutant, whether in noninducing or inducing conditions, contains a level of qa-1F mRNA that corresponds to the low level observed in uninduced wild-type cultures. These results corroborate the hypothesis (M. E. Case and N. H. Giles, Proc. Natl. Acad. Sci. USA 72:553-557, 1975; V. B. Patel, M. Schweizer, C. C. Dykstra, S. R. Kushner, and N. H. Giles, Proc. Natl. Acad. Sci. USA 78:5783-5787, 1981; L. Huiet, Proc. Natl. Acad. Sci. USA 81:1174-1178, 1984) that the qa-1F gene encodes an activator protein and acts positively in controlling transcription of itself and the other qa genes.


1985 ◽  
Vol 5 (12) ◽  
pp. 3593-3599 ◽  
Author(s):  
V B Patel ◽  
N H Giles

In Neurospora crassa, the qa-1F regulatory gene positively controls transcription of all genes in the quinic acid (qa) gene cluster. qa-1F is transcribed at a low, uninduced level but is subject to strong (50-fold), autogenous regulation as well as to control by the negative regulatory gene, qa-1S, and the inducer quinic acid. Cloned qa-1F DNA sequences hybridize to two related mRNAs of 2.9 and 3.0 kilobases. When wild-type (qa-1F+) cultures are transferred to inducing conditions, qa-1F mRNA increases for 4 h, remains somewhat level, and decreases after 8 to 10 h. That this control is autogenous, i.e., that the qa-1F gene controls the synthesis of its own mRNA, is indicated by the presence of approximately the same low level of qa-1F mRNA in poly(A)+ RNA from noninducible qa-1F- mutant cultures under inducing conditions as that observed in uninduced wild-type cultures. The qa-1S gene also regulates the transcription of qa-1F, since a qa-1S- mutant, whether in noninducing or inducing conditions, contains a level of qa-1F mRNA that corresponds to the low level observed in uninduced wild-type cultures. These results corroborate the hypothesis (M. E. Case and N. H. Giles, Proc. Natl. Acad. Sci. USA 72:553-557, 1975; V. B. Patel, M. Schweizer, C. C. Dykstra, S. R. Kushner, and N. H. Giles, Proc. Natl. Acad. Sci. USA 78:5783-5787, 1981; L. Huiet, Proc. Natl. Acad. Sci. USA 81:1174-1178, 1984) that the qa-1F gene encodes an activator protein and acts positively in controlling transcription of itself and the other qa genes.


Sign in / Sign up

Export Citation Format

Share Document