Exploring the size limit of protein diffusion through the periplasm in cyanobacterium Anabaena sp. PCC 7120 using the 13 kDa iLOV fluorescent protein |
| |
| Authors: | Li-Chen Zhang Véronique Risoul Amel Latifi John M. Christie Cheng-Cai Zhang |
| |
| Affiliation: | 1. Aix-Marseille Université, CNRS, Laboratoire de Chimie Bactérienne UMR 7283, 31 chemin Joseph Aiguier, 13009 Marseille cedex 20, France;2. Institute of Molecular Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, G12 8QQ, UK;1. State Key Laboratory of Cellular Stress Biology, School of Life Science, Xiamen University, Xiamen, Fujian 361005, People''s Republic of China;2. ARS, Animal Parasitic Diseases Laboratory, Beltsville, MD 20705, USA;1. College of Veterinary Medicine, Jilin Agricultural University, Changchun, China;2. Jilin Provincial Engineering Research Center of Animal Probiotics, Jilin Provincial Key Laboratory of Animal Microecology and Healthy Breeding, Jilin Agricultural University, Changchun, China;3. Key Laboratory of animal production and product quality safety of Ministry of Education, Jilin Agricultural University, Changchun, China;1. Rajiv Gandhi Biotechnology Centre, Rashtrasant Tukdoji Maharaj Nagpur University, L.I.T. Premises, Nagpur 440 033, Maharashtra, India;2. Sai Bioinfosys Institute of Bioinformatics Research, Raghuji Nagar, Nagpur 440 033, Maharashtra, India;1. Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA;2. Institute of Microbiology and Molecular Biology, University of Hohenheim, 70599 Stuttgart, Germany |
| |
| Abstract: | In the filamentous heterocyst-forming cyanobacterium Anabaena PCC 7120, vegetative cells and heterocysts are interdependent on each other and engaged in exchanges of metabolites for survival when grown under diazotrophic conditions. In this organism, the periplasm appears to be continuous along each filament, with a shared outer membrane; however, barriers exist preventing free diffusion of the fluorescent protein GFP (27 kDa) targeted into the periplasmic space. Here we expressed a smaller fluorescent protein iLOV (～13 kDa) fused to the All3333 (a putative homologue of NrtA) signal sequence corresponding to those recognized by the TAT protein translocation system, which exports iLOV to the periplasm of either heterocysts or vegetative cells. Fluorescence microscopy and immunoblot analysis indicated that the iLOV protein is translocated into the periplasm of the producing cell and properly processed, but does not diffuse to neighboring cells via the periplasm. Thus, periplasmic barriers appear to block diffusion of molecules with a size of 13 kDa, the minimum size tested thus far. Assuming that the physical barrier is the peptidoglycan sacculus, its pores might allow diffusion of molecules within the size range between the PatS pentapeptide and iLOV, thus between 0.53 kDa and 13 kDa. |
| |
| Keywords: | Periplasm Fluorescent protein iLOV GFP |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
