b'41Stanford graduate student Tyler Wittkopp (left) was lead author on the study, working with Carnegies Arthur Grossman (right) and other team members. Image courtesy Tyler Wittkoppranging from assembling photosynthetic complexesexposed to high light, suggesting an important role to influencing electron transport and carbon fixation. for CPLD49 under such conditions. The photosynthetic apparatus is made up of pigment- Grossman and colleagues also showed that CPLD49 protein complexes within specialized chloroplastplays a critical role in photosynthetic electron membranes called thylakoids. The major complexestransport and is necessary for the accumulation involved in the conversion of solar energy (i.e., light)of the cytochrome b 6 f complex; Chlamydomonas to chemical energy (i.e., sugars) include light-capturinglacking CPLD49 showed a nearly 90% loss of this photosystems and the cytochrome b 6 f complex.complex. Interestingly, CPLD49 appears to interact with another GreenCut protein, CPLD38, which is Photosynthetic electron transport is highlyalso critical for cytochrome b 6 f accumulation. How regulated and must be coordinated with cellularthese GreenCut proteins affect the cytochrome b 6 fand environmental cues. Using the green algacomplex is unknown, but they may be involved in Chlamydomonas reinhardtii, the team discoveredmaking a cofactor associated with the complex or that a GreenCut protein called CPLD49 wasaltering the nature of the membrane environment. critical for maintaining normal photosynthesis.These and other discoveries may provide unique A Chlamydomonas strain devoid of CPLD49 wasopportunities for engineering photosynthesis to unable to grow without a fixed carbon source whenfunction over a range of environmental conditions.'