An aromatic prenyltransferase-like gene HlPT-1 preferentially expressed in lupulin glands of hop

Abstract

Prenylated aromatic compounds represent the chemical components in the glandular trichomes (lupulin glands) of hops (Humulus lupulus, Cannabinaceae), which give the characteristic flavor and taste of beer. To isolate cDNAs for prenyltransferase recognizing aromatic substrates in hops, we constructed a cDNA library from the lupulin glands and randomly sequenced 11,233 EST clones, to obtain 6,613 non-redundant EST sequence information. Among them, we found an aromatic prenyltransferase-like gene (HlPT-1), which possessed three features of the plant aromatic prenyltransferase family, i.e., a D-rich motif, membrane-spanning domains, and a transit peptide. The tissue-specific expression study of HlPT-1 in the intact plant revealed this gene to be highly expressed in hop corns (female flowers), especially in the lupulin glands. Subcellular localization analysis using GFP fusion proteins suggested that HlPT-1 was localized to plastids. Phylogenetic analysis predicted that the HlPT-1 gene evolved from homogentisate prenyltransferases involved with vitamin E and plastoquinone biosynthesis.

Molecular Characterization of a Membrane-bound Prenyltransferase Specific for Isoflavone from Sophora flavescens

“…phenylpropanes, xanthones, coumarins, and phloroglucinols is also highly expected to comprehend a thorough overview of the phylogenetic relationship of these prenyltransferases. One of those candidates is the prenyltransferase gene, HlPT1, isolated from hop (Humulus lupulus) (33), whose amino acid sequence is classified as a unique member (Fig. 2).…”

A Heteromeric Membrane-Bound Prenyltransferase Complex from Hop Catalyzes Three Sequential Aromatic Prenylations in the Bitter Acid Pathway

“…One candidate gene (encoding a peptide of 414 amino acids, TCHL40971, in the TrichOME database) was found to be 98.5% identical to the prenyltransferase gene (GenBank accession no. AB543053; designated as HlPT-1) cloned by Yazaki's group from hop 'Kirin II' (Tsurumaru et al, 2010). The sequence difference between these two proteins was probably due to the different hop cultivar ('Nugget') we used for cDNA library construction; we thus designated this HlPT-1 allele as HlPT1-like (HlPT1L).…”

Molecular Cloning and Characterization of a Geranyl Diphosphate-Specific Aromatic Prenyltransferase from Lemon

“…iPSORT predicted that ClPT1 has a transit peptide at its N terminus, and PSORT found a putative cleavage site between G36 and G37 (Supplemental Fig. S1A Collakova and DellaPenna, 2001;Savidge et al, 2002;Yazaki et al, 2002;Ohara et al, 2006;Sadre et al, 2006;Sasaki et al, 2008;Tsurumaru et al, 2010;Yang et al, 2011;Karamat et al, 2014). ClPT1 could not be grouped into any previously identified clade, including membrane-bound PTs ( Fig.…”

“…Since then, genes encoding various flavonoid PTs have been identified in Leguminosae (Akashi et al, 2009;Sasaki et al, 2011;Shen et al, 2012). Although other prenylated aromatic compounds, including coumarins, xanthons, phenylpropanoids, and phloroglucinols, have been isolated from many plant species, no gene encoding a PT for those aromatics has been isolated, except for the gene encoding a phloroglucinol-specific enzyme (HlPT1) from hops (Humulus lupulus) and a the recently isolated coumarin dimethylallyltransferase from parsley (Tsurumaru et al, 2010Karamat et al, 2014). These isolated plant aromatic PTs show strong preference for dimethylallyl diphosphate (DMAPP) as the prenyl donor substrate, although in nature, many geranylated phenolics and less farnesylated phenolics have been described.…”