In:
New Phytologist, Wiley, Vol. 213, No. 1 ( 2017-01), p. 193-205
Abstract:
Diatom plastids show several peculiarities when compared with primary plastids of higher plants or algae. They are surrounded by four membranes and depend on nucleotide uptake because, unlike in plants, nucleotide de novo synthesis exclusively occurs in the cytosol. Previous analyses suggest that two specifically adapted nucleotide transporters ( NTT s) facilitate the required passage of nucleotides across the innermost plastid membrane. However, nucleotide transport across the additional plastid membranes remains to be clarified. Phylogenetic studies, transport assays with the recombinant protein as well as GFP ‐based targeting analyses allowed detailed characterization of a novel isoform ( Pt NTT 5) of the six NTT s of Phaeodactylum tricornutum . Pt NTT 5 exhibits low amino acid similarities and is only distantly related to all previously characterized NTT s. However, in a heterologous expression system, it acts as a nucleotide antiporter and prefers various (deoxy‐) purine nucleotides as substrates. Interestingly, Pt NTT 5 is probably located in the endoplasmic reticulum, which in diatoms also represents the outermost plastid membrane. Pt NTT 5, with its unusual transport properties, phylogeny and localization, can be taken as further evidence for the establishment of a sophisticated and specifically adapted nucleotide transport system in diatom plastids.
Type of Medium:
Online Resource
ISSN:
0028-646X
,
1469-8137
DOI:
10.1111/nph.2017.213.issue-1
Language:
English
Publisher:
Wiley
Publication Date:
2017
detail.hit.zdb_id:
208885-X
detail.hit.zdb_id:
1472194-6