Abstract
The sigB and sigC genes, encoding two alternative sigma factors of the unicellular marine cyanobacterium Synechococcus sp. PCC 7002, were cloned and characterized. Strains in which the sigB and sigC genes were insertionally inactivated were viable under standard laboratory conditions, indicating that SigB and SigC are group 2 sigma factors. Starvation for either nitrogen or carbon caused an increase in sigB mRNA levels. Transcripts for the sigC gene initially increased but then decreased during nitrogen and carbon starvation. The SigC protein could not be identified in cyanobacterial extracts using antisera to Synechococcus sp. PCC 7002 SigA or RpoD from Bacillus subtilis. The ratio of the principal vegetative sigma factor, SigA, to SigB decreased during either nitrogen starvation or carbon starvation, and the levels of SigB also increased in the sigC mutant strain. These results imply that SigB and SigC play roles in modifying transcription in response to changes in carbon and nitrogen availability in this cyanobacterium.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 3807-3818 |
| Number of pages | 12 |
| Journal | Microbiology |
| Volume | 143 |
| Issue number | 12 |
| DOIs | |
| State | Published - Jan 1 1997 |
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All Science Journal Classification (ASJC) codes
- Microbiology
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Expression of two alternative sigma factors of Synechococcus sp. strain PCC 7002 is modulated by carbon and nitrogen stress. / Caslake, Laurie F.; Gruber, Tanja M.; Bryant, Donald Ashley.
In: Microbiology, Vol. 143, No. 12, 01.01.1997, p. 3807-3818.Research output: Contribution to journal › Article
TY - JOUR
T1 - Expression of two alternative sigma factors of Synechococcus sp. strain PCC 7002 is modulated by carbon and nitrogen stress
AU - Caslake, Laurie F.
AU - Gruber, Tanja M.
AU - Bryant, Donald Ashley
PY - 1997/1/1
Y1 - 1997/1/1
N2 - The sigB and sigC genes, encoding two alternative sigma factors of the unicellular marine cyanobacterium Synechococcus sp. PCC 7002, were cloned and characterized. Strains in which the sigB and sigC genes were insertionally inactivated were viable under standard laboratory conditions, indicating that SigB and SigC are group 2 sigma factors. Starvation for either nitrogen or carbon caused an increase in sigB mRNA levels. Transcripts for the sigC gene initially increased but then decreased during nitrogen and carbon starvation. The SigC protein could not be identified in cyanobacterial extracts using antisera to Synechococcus sp. PCC 7002 SigA or RpoD from Bacillus subtilis. The ratio of the principal vegetative sigma factor, SigA, to SigB decreased during either nitrogen starvation or carbon starvation, and the levels of SigB also increased in the sigC mutant strain. These results imply that SigB and SigC play roles in modifying transcription in response to changes in carbon and nitrogen availability in this cyanobacterium.
AB - The sigB and sigC genes, encoding two alternative sigma factors of the unicellular marine cyanobacterium Synechococcus sp. PCC 7002, were cloned and characterized. Strains in which the sigB and sigC genes were insertionally inactivated were viable under standard laboratory conditions, indicating that SigB and SigC are group 2 sigma factors. Starvation for either nitrogen or carbon caused an increase in sigB mRNA levels. Transcripts for the sigC gene initially increased but then decreased during nitrogen and carbon starvation. The SigC protein could not be identified in cyanobacterial extracts using antisera to Synechococcus sp. PCC 7002 SigA or RpoD from Bacillus subtilis. The ratio of the principal vegetative sigma factor, SigA, to SigB decreased during either nitrogen starvation or carbon starvation, and the levels of SigB also increased in the sigC mutant strain. These results imply that SigB and SigC play roles in modifying transcription in response to changes in carbon and nitrogen availability in this cyanobacterium.
UR - http://www.scopus.com/inward/record.url?scp=0031466505&partnerID=8YFLogxK
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U2 - 10.1099/00221287-143-12-3807
DO - 10.1099/00221287-143-12-3807
M3 - Article
C2 - 9421905
AN - SCOPUS:0031466505
VL - 143
SP - 3807
EP - 3818
JO - Microbiology
JF - Microbiology
SN - 1350-0872
IS - 12
ER -