title: AtLACS7 interacts with the TPR domains of the PTS1 receptor PEX5.
abstract: Long-chain acyl-CoA synthetases (LACSs) activate fatty acids for further metabolism and are encoded by a multi-gene family in Arabidopsis. AtLACS6 possesses a type 2 (PTS2) peroxisomal targeting sequence, whilst AtLACS7 has both a type 1 and type 2 peroxisomal targeting sequence. AtLACS7 was used as bait in a yeast two-hybrid screen. Multiple clones of the PTS1 receptor PEX5 were isolated. Quantitative beta-galactosidase assay indicated that full-length PEX5 interacts with AtLACS7 with higher affinity than the TPR domains alone. The interaction between PEX5 and AtLACS7 was confirmed by co-immunoprecipitation and shown to be specific for the PTS1, therefore the AtLACS7 PTS1 is accessible to bind PEX5 in the full-length AtLACS7 protein. The expression profile of AtLACS6, AtLACS7, AtPEX5, and AtPEX7 revealed that AtLACS6 and 7 have distinct patterns of expression and we speculate that the possession of two targeting signals may be advantageous for the import of AtLACS7 when receptors may be limiting.
authors.affiliation: Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, Università degli Studi di Lecce, Italy.
authors.forename: Stefania
authors.initials: S
authors.lastname: Bonsegna
authors.forename: Stephen P
authors.initials: SP
authors.lastname: Slocombe
authors.forename: Luigi
authors.initials: L
authors.lastname: De Bellis
authors.forename: Alison
authors.initials: A
authors.lastname: Baker
mesh_terms: D017360:Arabidopsis / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000737:chemistry* / Q000378:metabolism*; D001665:Binding Sites; D003066:Coenzyme A Ligases / Q000737:chemistry* / Q000378:metabolism*; D000074435:Peroxisome-Targeting Signal 1 Receptor; D011485:Protein Binding; D025941:Protein Interaction Mapping; D017434:Protein Structure, Tertiary; D018160:Receptors, Cytoplasmic and Nuclear / Q000737:chemistry* / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D000074435:Peroxisome-Targeting Signal 1 Receptor; D018160:Receptors, Cytoplasmic and Nuclear; D003066:Coenzyme A Ligases; C470375:LACS7 protein, Arabidopsis