Parthompong Ves-Urai1, Sucheewin Krobthong2, Karnpitcha Thongsuk3, Sittiruk Roytrakul4, Chotika Yokthongwattana5,6. 1. Interdisciplinary Program in Genetic Engineering, Graduate School, Kasetsart University, Bangkok, Thailand. 2. National Center for Genetic Engineering and Biotechnology, 113 Thailand Science Park, Phahonyothin Rd., Pathumthani, 12120, Thailand. 3. Department of Biochemistry, Faculty of Science, Kasetsart University, 50 Ngamwongwan Rd., Bangkok, 10900, Thailand. 4. Functional Ingredients and Food Innovation Research Group, National Center for Genetic Engineering and Biotechnology, 113 Thailand Science Park, Phahonyothin Rd., Pathumthani, 12120, Thailand. 5. Department of Biochemistry, Faculty of Science, Kasetsart University, 50 Ngamwongwan Rd., Bangkok, 10900, Thailand. fscicks@ku.ac.th. 6. Omics Center for Agriculture, Bioresources, Food and Health, Kasetsart University (OmiKU), Kasetsart University, 50 Ngam Wong Wan Road, Chatuchak, Bangkok, 10900, Thailand. fscicks@ku.ac.th.
Abstract
MAIN CONCLUSION: Secretome analysis of a salt-tolerant and control Chlamydomonas reinhardtii revealed 514 differentially expressed proteins. Membrane transport and trafficking, signal transduction and channel proteins were up-regulated in the ST secretome. Salinity is a major abiotic stress that limits crop production worldwide. Multiple adverse effects have been reported in many living organisms exposed to high-saline concentrations. Chlamydomonas reinhardtii is known for secreting proteins in response to many environmental stresses. A salinity-tolerant (ST) strain of Chlamydomonas has been developed, whose cells were able to grow at 300 mM NaCl. The current study analyzed the secretomes of ST grown in TAP medium supplemented with 300 mM NaCl and the laboratory strain CC-503 grown in TAP medium without NaCl supplement. In total, 514 secreted proteins were identified of which 203 were up-regulated and 110 were down-regulated. Bioinformatic analysis predicted 168 proteins to be secreted or in the conventional secretory pathway. Out of these, 70 were up-regulated, while 51 proteins were down-regulated. Proteins involved in membrane transport and trafficking, signal transduction and channel proteins were altered in their expression in the ST secretome, suggesting the response of saline stress acts toward not only the intracellular pool of proteins but also the extracellular proteins. This also suggested that the secreted proteins might have roles in the extracellular space. Signal peptide (SP) prediction revealed that almost 40% of the predicted secreted proteins contained a signal peptide; however, a high proportion of proteins lacked an SP, suggesting that these proteins might be secreted through an unconventional protein secretion pathway.
MAIN CONCLUSION: Secretome analysis of a salt-tolerant and control Chlamydomonas reinhardtii revealed 514 differentially expressed proteins. Membrane transport and trafficking, signal transduction and channel proteins were up-regulated in the ST secretome. Salinity is a major abiotic stress that limits crop production worldwide. Multiple adverse effects have been reported in many living organisms exposed to high-saline concentrations. Chlamydomonas reinhardtii is known for secreting proteins in response to many environmental stresses. A salinity-tolerant (ST) strain of Chlamydomonas has been developed, whose cells were able to grow at 300 mM NaCl. The current study analyzed the secretomes of ST grown in TAP medium supplemented with 300 mM NaCl and the laboratory strain CC-503 grown in TAP medium without NaCl supplement. In total, 514 secreted proteins were identified of which 203 were up-regulated and 110 were down-regulated. Bioinformatic analysis predicted 168 proteins to be secreted or in the conventional secretory pathway. Out of these, 70 were up-regulated, while 51 proteins were down-regulated. Proteins involved in membrane transport and trafficking, signal transduction and channel proteins were altered in their expression in the ST secretome, suggesting the response of saline stress acts toward not only the intracellular pool of proteins but also the extracellular proteins. This also suggested that the secreted proteins might have roles in the extracellular space. Signal peptide (SP) prediction revealed that almost 40% of the predicted secreted proteins contained a signal peptide; however, a high proportion of proteins lacked an SP, suggesting that these proteins might be secreted through an unconventional protein secretion pathway.
Entities:
Keywords:
Chlamydomonas; Environmental stress; Salinity stress; Secretome; Signal peptide; Unconventional protein secretion