Phenolamides: Bridging polyamines to the phenolic metabolism

Evolutionarily Distinct BAHD N-acyltransferases are Responsible for Natural Variation of Aromatic Amine Conjugates in Rice

“…While BAHD proteins are responsible for the acylation of aliphatic and arylmonoamine acceptors, GNAT enzymes are active on arylamines (Bassard et al, 2010). Although they are from two distinct protein families that show low sequence identity, the BAHD N-acyltransferases, Os-THTs and Os-TBTs, identified in our study demonstrate that proteins from both families can act on aryldiamines (Tables 2 and 3; Jang et al, 2004;Kang et al, 2006).…”

“…Since the selectivity on hydroxycinnamoyl-CoA is present in BAHD enzymes of all plant species (D'Auria, 2006;Bassard et al, 2010), from moss to legumes, we assume that Os-THTs were derived from one ancient BAHD protein that preserved its selectivity for acyl donors and evolved new catalytic capabilities in selecting tryptamine/serotonin as acyl acceptors. Protein BLAST searches in Phytozome and NCBI databases did not find orthologs among the 29 core Eudicotyledons and three Gymnosperms (even at 40% identity) but did detect them in Amborella trichopoda and Nelumbo nucifera and in one primitive Eudicotyledon, Aquiclegia coerrulea ( Figure 10B).…”

“…Phenolamides (PAs), also referred to as hydroxycinnamic acid amides or phenylamides, are the hydroxycinnamoyl acylated products of the mono-, di-, or triphenolic acid (coumaric, caffeic, or ferulic acid) substitutions of polyamines (putrescine, spermidine, agmatine, tryptamine, and serotonin) or arylmonoamines such as tyramine, octopamine, and anthranilate ( Figure 1; Bienz et al, 2005;Edreva et al, 2007;Bassard et al, 2010). PAs are a diverse group of specialized metabolites found in many plants, including wheat (Triticum aestivum), barley (Hordeum vulgare), rice (Oryza sativa), and maize (Zea mays) (Martin-Tanguy et al, 1978;Martin et al, 1985;Facchini et al, 2002;Edreva et al, 2007;Bassard et al, 2010).…”

“…PAs are a diverse group of specialized metabolites found in many plants, including wheat (Triticum aestivum), barley (Hordeum vulgare), rice (Oryza sativa), and maize (Zea mays) (Martin-Tanguy et al, 1978;Martin et al, 1985;Facchini et al, 2002;Edreva et al, 2007;Bassard et al, 2010). Accumulating evidence shows that PAs play an important role in plant defense responses against pathogens and insect herbivores (Newman et al, 2001;Tanaka et al, 2003;Kaur et al, 2010;Park et al, 2014).…”

“…Analysis of their amino acid sequences revealed that all these enzymes belong to the GCN5-related N-acetyltransferases (GNAT) protein family, which also includes mammalian spermidine/spermine acetyltransferase and several microbial antibiotic N-acetyltransferases (Lu et al, 1996;Farmer et al, 1999;Kang et al, 2006). In contrast to the situation where PAs of arylamine moieties are mainly biosynthesized by the GNAT family of enzymes, the biosynthesis of the aliphatic type of phenolamides is exclusively the domain of BAHD acyltransferases (D'Auria, 2006;Bassard et al, 2010). The BAHD acyltransferase family was named according to the first letter of each of the first four biochemically characterized enzymes of this family BEAT (benzoyl alcohol O-acetyltransferase), AHCT (anthocyanin O-hydroxycinnamoyl transferase), HCBT (anthranilate N-hydroxycinnamoyl/benzoyl transferase), and DAT (deacetyl vindoline 4-O-acetyltransferase) (St-Pierre and De Luca, 2000).…”