Role of signal peptides in targeting of proteins in cyanobacteria

• Published in: Journal of Bacteriology 1994-04, Vol.176 (7), p.1857-1864
• Main Authors: Mackle, M.M, Zilinskas, B.A
• Format: Article
• Language: English
• Subjects: ACILTRANSFERASA; ACYLTRANSFERASE; ADN RECOMBINADO; ADN RECOMBINE; Amino Acid Sequence; BACTERIA; Bacteriology; Base Sequence; Biological and medical sciences; Biological Transport; Carrier Proteins - genetics; Carrier Proteins - metabolism; Cell Compartmentation; Cellular biology; Chloramphenicol O-Acetyltransferase - genetics; Chloramphenicol O-Acetyltransferase - metabolism; Cyanobacteria - genetics; Cyanobacteria - metabolism; CYANOPHYTA; Escherichia coli Proteins; Flowers & plants; Fundamental and applied biological sciences. Psychology; GENE; GENES; IMMUNOLOGIE; INMUNOLOGIA; MEMBRANAS CELULARES; MEMBRANE CELLULAIRE; METABOLISME DES PROTEINES; METABOLISMO PROTEICO; Microbiology; Molecular Sequence Data; Periplasmic Binding Proteins; Permeability, membrane transport, intracellular transport; PIGMENT; PIGMENTOS; PLASTE; PLASTIDIOS; Plastocyanin - genetics; Plastocyanin - metabolism; Protein Precursors - metabolism; Protein Sorting Signals - genetics; Protein Sorting Signals - metabolism; PROTEINAS; PROTEINE; Proteins; Recombinant Fusion Proteins - metabolism; Subcellular Fractions; Synechococcus; Thiosulfate Sulfurtransferase - genetics; Thiosulfate Sulfurtransferase - metabolism; TRANSFORMACION GENETICA; TRANSFORMATION GENETIQUE
• ISSN: 0021-9193; 1098-5530; 1067-8832
• DOI: 10.1128/jb.176.7.1857-1864.1994

Proteins of cyanobacteria may be transported across one of two membrane systems: the typical eubacterial cell envelope (consisting of an inner membrane, periplasmic space, and an outer membrane) and the photosynthetic thylakoids. To investigate the role of signal peptides in targeting in cyanobacteria, Synechococcus sp. strain PCC 7942 was transformed with vectors carrying the chloramphenicol acetyltransferase reporter gene fused to coding sequences for one of four different signal peptides. These included signal peptides of two proteins of periplasmic space origin (one from Escherichia coli and the other from Synechococcus sp. strain PCC 7942) and two other signal peptides of proteins located in the thylakoid lumen (one from a cyanobacterium and the other from a higher plant). The location of the gene fusion products expressed in Synechococcus sp. strain PCC 7942 was determined by a chloramphenicol acetyltransferase enzyme-linked immunosorbent assay of subcellular fractions. The distribution pattern for gene fusions with periplasmic signal peptides was different from that of gene fusions with thylakoid lumen signal peptides. Primary sequence analysis revealed conserved features in the thylakoid lumen signal peptides that were absent from the periplasmic signal peptides. These results suggest the importance of the signal peptide in protein targeting in cyanobacteria and point to the presence of signal peptide features conserved between chloroplasts and cyanobacteria for targeting of proteins to the thylakoid lumen