title: MARINE-EXPRESS: taking advantage of high throughput cloning and expression strategies for the post-genomic analysis of marine organisms.
abstract: BACKGROUND
  The production of stable and soluble proteins is one of the most important steps prior to structural and functional studies of biological importance. We investigated the parallel production in a medium throughput strategy of genes coding for proteins from various marine organisms, using protocols that involved recombinatorial cloning, protein expression screening and batch purification. This strategy was applied in order to respond to the need for post-genomic validation of the recent success of a large number of marine genomic projects. Indeed, the upcoming challenge is to go beyond the bioinformatic data, since the bias introduced through the genomes of the so called model organisms leads to numerous proteins of unknown function in the still unexplored world of the oceanic organisms.
  
  
  RESULTS
  We present here the results of expression tests for 192 targets using a 96-well plate format. Genes were PCR amplified and cloned in parallel into expression vectors pFO4 and pGEX-4T-1, in order to express proteins N-terminally fused to a six-histidine-tag and to a GST-tag, respectively. Small-scale expression and purification permitted isolation of 84 soluble proteins and 34 insoluble proteins, which could also be used in refolding assays. Selected examples of proteins expressed and purified to a larger scale are presented.
  
  
  CONCLUSIONS
  The objective of this program was to get around the bottlenecks of soluble, active protein expression and crystallization for post-genomic validation of a number of proteins that come from various marine organisms. Multiplying the constructions, vectors and targets treated in parallel is important for the success of a medium throughput strategy and considerably increases the chances to get rapid access to pure and soluble protein samples, needed for the subsequent biochemical characterizations. Our set up of a medium throughput strategy applied to genes from marine organisms had a mean success rate of 44% soluble protein expression from marine bacteria, archaea as well as eukaryotic organisms. This success rate compares favorably with other protein screening projects, particularly for eukaryotic proteins. Several purified targets have already formed the base for experiments aimed at post-genomic validation.
authors.affiliation: UPMC Univ Paris 6, UMR 7139 Végétaux marins et Biomolécules, LIA DIAMS, Station Biologique, Roscoff, France.
authors.forename: Agnès
authors.initials: A
authors.lastname: Groisillier
authors.forename: Cécile
authors.initials: C
authors.lastname: Hervé
authors.forename: Alexandra
authors.initials: A
authors.lastname: Jeudy
authors.forename: Etienne
authors.initials: E
authors.lastname: Rebuffet
authors.forename: Pierre F
authors.initials: PF
authors.lastname: Pluchon
authors.forename: Yann
authors.initials: Y
authors.lastname: Chevolot
authors.forename: Didier
authors.initials: D
authors.lastname: Flament
authors.forename: Claire
authors.initials: C
authors.lastname: Geslin
authors.forename: Isabel M
authors.initials: IM
authors.lastname: Morgado
authors.forename: Déborah
authors.initials: D
authors.lastname: Power
authors.forename: Margherita
authors.initials: M
authors.lastname: Branno
authors.forename: Hervé
authors.initials: H
authors.lastname: Moreau
authors.forename: Gurvan
authors.initials: G
authors.lastname: Michel
authors.forename: Catherine
authors.initials: C
authors.lastname: Boyen
authors.forename: Mirjam
authors.initials: M
authors.lastname: Czjzek
mesh_terms: D000818:Animals; D019843:Archaeal Proteins / Q000235:genetics* / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D003001:Cloning, Molecular; D019295:Computational Biology; D056890:Eukaryota / Q000235:genetics*; D041965:Flavobacteriaceae / Q000235:genetics; D057166:High-Throughput Screening Assays; D010957:Plasmids / Q000235:genetics / Q000378:metabolism; D043903:Pyrococcus abyssi / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D021541:Sea Bream / Q000235:genetics
chemical_list: D019843:Archaeal Proteins; D001426:Bacterial Proteins; D011993:Recombinant Fusion Proteins