title: Involvement of mammalian bilitranslocase-like protein(s) in chlorophyll catabolism of Pisum sativum L. tissues.
abstract: Putative pea bilin and cyclic tetrapyrrole transporter proteins were identified by means of an antibody raised against a bilirubin-interacting aminoacidic sequence of mammalian bilitranslocase (TC No. 2.A.65.1.1). The immunochemical approach showed the presence of several proteins mostly in leaf microsomal, chloroplast and tonoplast vesicles. In these membrane fractions, electrogenic bromosulfalein transport activity was also monitored, being specifically inhibited by anti-bilitranslocase sequence antibody. Moreover, the inhibition of transport activity in pea leaf chloroplast vesicles, by both the synthetic cyclic tetrapyrrole chlorophyllin and the heme catabolite biliverdin, supports the involvement of some of these proteins in the transport of linear/cyclic tetrapyrroles during chlorophyll metabolism. Immunochemical localization in chloroplast sub-compartments revealed that these putative bilitranslocase-like transporters are restricted to the thylakoids only, suggesting their preferential implication in the uptake of cyclic tetrapyrrolic intermediates from the stroma during chlorophyll biosynthesis. Finally, the presence of a conserved bilin-binding sequence in different proteins (enzymes and transporters) from divergent species is discussed in an evolutionary context.
authors: Department of Agricultural and Environmental Sciences, Section of Plant Biology, University of Udine, Via delle Scienze 91, 33100, Udine, Italy.
authors: Carlo
authors: C
authors: Peresson
authors: Elisa
authors: E
authors: Petrussa
authors: Antonio
authors: A
authors: Filippi
authors: Federica
authors: F
authors: Tramer
authors: Sabina
authors: S
authors: Passamonti
authors: Uros
authors: U
authors: Rajcevic
authors: Sendi
authors: S
authors: Montanič
authors: Michela
authors: M
authors: Terdoslavich
authors: Vladka
authors: V
authors: Čurin Šerbec
authors: Angelo
authors: A
authors: Vianello
authors: Enrico
authors: E
authors: Braidot
mesh_terms: D000818:Animals; D001693:Biological Transport, Active; D002570:Ceruloplasmin; D002734:Chlorophyll / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism*; D026901:Membrane Transport Proteins / Q000378:metabolism*; D018532:Pisum sativum / Q000378:metabolism*
chemical_list: D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D002734:Chlorophyll; D002570:Ceruloplasmin; C033838:bilitranslocase