TY - JOUR
T1 - Targeted mutagenesis of acyl-lipid desaturases in Synechocystis
T2 - Evidence for the important roles of polyunsaturated membrane lipids in growth, respiration and photosynthesis
AU - Tasaka, Yasushi
AU - Gombos, Zoltán
AU - Nishiyama, Yoshitaka
AU - Mohanty, Prasanna
AU - Ohba, Tetsuhiko
AU - Ohki, Kazuo
AU - Murata, Norio
PY - 1996/12/2
Y1 - 1996/12/2
N2 - Acyl-lipid desaturases introduce double bonds (unsaturated bonds) at specifically defined positions in fatty acids that are esterified to the glycerol backbone of membrane glycerolipids. The desA, desB and desD genes of Synechocystis sp. PCC 6803 encode acyl-lipid desaturases that introduce double bonds at the Δ12, ω3 and Δ6 positions of C18 fatty acids respectively. The mutation of each of these genes by insertion of an antibiotic resistance gene cartridge completely eliminated the corresponding desaturation reaction. This system allowed us to manipulate the number of unsaturated bonds in membrane glycerolipids in this organism in a step-wise manner. Comparisons of the variously mutated cells revealed that the replacement of all polyunsaturated fatty acids by a monounsaturated fatty acid suppressed growth of the cells at low temperature and, moreover, it decreased the tolerance of the cells to photoinhibition of photosynthesis at low temperature by suppressing recovery of the photosystem II protein complex from photoinhibitory damage. However, the replacement of tri- and tetraunsaturated fatty acids by a diunsaturated fatty acid did not have such effects. These findings indicate that polyunsaturated fatty acids are important in protecting the photosynthetic machinery from photoinhibition at low temperatures.
AB - Acyl-lipid desaturases introduce double bonds (unsaturated bonds) at specifically defined positions in fatty acids that are esterified to the glycerol backbone of membrane glycerolipids. The desA, desB and desD genes of Synechocystis sp. PCC 6803 encode acyl-lipid desaturases that introduce double bonds at the Δ12, ω3 and Δ6 positions of C18 fatty acids respectively. The mutation of each of these genes by insertion of an antibiotic resistance gene cartridge completely eliminated the corresponding desaturation reaction. This system allowed us to manipulate the number of unsaturated bonds in membrane glycerolipids in this organism in a step-wise manner. Comparisons of the variously mutated cells revealed that the replacement of all polyunsaturated fatty acids by a monounsaturated fatty acid suppressed growth of the cells at low temperature and, moreover, it decreased the tolerance of the cells to photoinhibition of photosynthesis at low temperature by suppressing recovery of the photosystem II protein complex from photoinhibitory damage. However, the replacement of tri- and tetraunsaturated fatty acids by a diunsaturated fatty acid did not have such effects. These findings indicate that polyunsaturated fatty acids are important in protecting the photosynthetic machinery from photoinhibition at low temperatures.
KW - Acyl-lipid desaturase
KW - Membrane glycerolipid
KW - Photoinhibition
KW - Synechocystis sp. PCC 6803
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U2 - 10.1002/j.1460-2075.1996.tb01033.x
DO - 10.1002/j.1460-2075.1996.tb01033.x
M3 - Article
C2 - 8978669
AN - SCOPUS:0029804115
VL - 15
SP - 6416
EP - 6425
JO - EMBO Journal
JF - EMBO Journal
SN - 0261-4189
IS - 23
ER -