Cyanobacterial psbA families in Anabaena and Synechocystis encode trace, constitutive and UVB-induced D1 isoforms

@article{citeulike:2582804, abstract = {Cyanobacteria cope with UVB induced photoinhibition of Photosystem II by regulating multiple psbA genes to boost the expression of D1 protein (in Synechocystis sp. PCC6803), or to exchange the constitutive D1:1 protein to an alternate D1:2 isoform (in Synechococcus sp. PCC7942). To define more general patterns of cyanobacterial psbA expression, we applied moderately photoinhibitory UVB to Anabaena sp. PCC7120 and tracked the expression of its five psbA genes. psbAI, encoding a D1:1 protein isoform characterized by a Gln130, represented the majority of the psbA transcript pool under control conditions. psbAI transcripts decreased upon UVB treatment but the total psbA transcript pool increased 3.5 fold within 90 min as a result of sharply increased psbAII, psbAIV and psbAIII transcripts encoding an alternate D1:2 protein isoform characterized by Glu130, similar to that of Synechococcus. Upon UVB treatment the relaxation of flash induced chlorophyll fluorescence showed a characteristic acceleration of a decay phase likely associated with the exchange from the D1:1 protein isoform encoded by psbAI to the alternate D1:2 isoform encoded by psbAIV, psbAII and psbAIII. Throughout the UVB treatment the divergent psbA0 made only a trace contribution to the total psbA transcript pool. This suggests a similarity to the divergent psbAI gene from Synechocystis, whose natural expression we demonstrate for the first time at a trace level similar to psbA0 in Anabaena. These trace-expressed psbA genes in two different cyanobacteria raise questions concerning the functions of these divergent genes.}, author = {Sicora, Cosmin I. and Appleton, Sarah E. and Brown, Christopher M. and Chung, Jonathon and Chandler, Jillian and Cockshutt, Amanda M. and Vass, Imre and Campbell, Douglas A. }, citeulike-article-id = {2582804}, doi = {10.1016/j.bbabio.2005.11.002}, journal = {Biochimica et Biophysica Acta (BBA) - Bioenergetics}, keywords = {fam, psba, uvb}, month = {January}, number = {1}, pages = {47--56}, posted-at = {2008-03-24 21:14:06}, priority = {3}, title = {Cyanobacterial psbA families in Anabaena and Synechocystis encode trace, constitutive and UVB-induced D1 isoforms}, url = {http://dx.doi.org/10.1016/j.bbabio.2005.11.002}, volume = {1757}, year = {2006} }

TY - JOUR ID - citeulike:2582804 TI - Cyanobacterial psbA families in Anabaena and Synechocystis encode trace, constitutive and UVB-induced D1 isoforms JF - Biochimica et Biophysica Acta (BBA) - Bioenergetics VL - 1757 IS - 1 SP - 47 EP - 56 N2 - Cyanobacteria cope with UVB induced photoinhibition of Photosystem II by regulating multiple psbA genes to boost the expression of D1 protein (in Synechocystis sp. PCC6803), or to exchange the constitutive D1:1 protein to an alternate D1:2 isoform (in Synechococcus sp. PCC7942). To define more general patterns of cyanobacterial psbA expression, we applied moderately photoinhibitory UVB to Anabaena sp. PCC7120 and tracked the expression of its five psbA genes. psbAI, encoding a D1:1 protein isoform characterized by a Gln130, represented the majority of the psbA transcript pool under control conditions. psbAI transcripts decreased upon UVB treatment but the total psbA transcript pool increased 3.5 fold within 90 min as a result of sharply increased psbAII, psbAIV and psbAIII transcripts encoding an alternate D1:2 protein isoform characterized by Glu130, similar to that of Synechococcus. Upon UVB treatment the relaxation of flash induced chlorophyll fluorescence showed a characteristic acceleration of a decay phase likely associated with the exchange from the D1:1 protein isoform encoded by psbAI to the alternate D1:2 isoform encoded by psbAIV, psbAII and psbAIII. Throughout the UVB treatment the divergent psbA0 made only a trace contribution to the total psbA transcript pool. This suggests a similarity to the divergent psbAI gene from Synechocystis, whose natural expression we demonstrate for the first time at a trace level similar to psbA0 in Anabaena. These trace-expressed psbA genes in two different cyanobacteria raise questions concerning the functions of these divergent genes. KW - fam KW - psba KW - uvb AU - Sicora, Cosmin AU - Appleton, Sarah AU - Brown, Christopher AU - Chung, Jonathon AU - Chandler, Jillian AU - Cockshutt, Amanda AU - Vass, Imre AU - Campbell, Douglas PY - 2006/01// UR - http://dx.doi.org/10.1016/j.bbabio.2005.11.002 ER -