Novel Occurrence of Uncommon Polyamines in Higher Plants

Abstract

Diamines and polyamines are ubiquitous components of living cells, and apparently are involved in numerous cellular and physiological processes. Certain "uncommon" polyamines have limited distribution in nature and have been associated primarily with organisms adapted to extreme environments, although the precise function of these polyamines in such organisms is unknown. This article summarizes current knowledge regarding the occurrence in higher plants of the uncommon polyamines related to and including norspermidine and norspermine. A putative biosynthetic pathway to account for the occurrences of these uncommon polyamines in higher plants is presented, with a summary of the supporting evidence indicating the existence of the requisite enzymatic activities in alfalfa, Medicago sativa L.The term "polyamines" is used here as a collective term for the naturally occurring diamines

Repeated Evolution of the Pyrrolizidine Alkaloid–Mediated Defense System in Separate Angiosperm Lineages w⃞

“…This universal availability of homospermidine as the essential precursor of the necine base moiety of all PAs may have been a prerequisite for the repeated establishment of this pathway in angiosperm evolution. Elevated levels of homospermidine have been described for only a few plants, which is the reason for it being regarded as a rare polyamine (Kuehn et al, 1990;Hamana et al, 1992Hamana et al, , 1994. Research is in progress to identify and characterize the enzymes responsible for the elevated homospermidine content in those plants.…”

Putrescine Importer PlaP Contributes to Swarming Motility and Urothelial Cell Invasion in Proteus mirabilis

“…The basic polyamines are putrescine, spermidine, and spermine, and it has been reported that several plants (1) and bacteria (2) produce a variety of unusual polyamines such as norspermidine. Polyamines are widely distributed from prokaryotic cells (3) to higher plants and animals (4), and polyamines play important roles in a variety of cellular functions, including translation, transcription, and chromatin remodeling.…”

A Novel Putrescine Importer Required for Type 1 Pili-driven Surface Motility Induced by Extracellular Putrescine in Escherichia coli K-12

“…Basic polyamines are putrescine, spermidine, and spermine. In addition, a variety of unusual polyamines has been reported in several plants (1) and bacteria (2). Polyamines are widely distributed from prokaryotic (3) to eukaryotic cells (4) and are found at especially high concentrations in proliferating cells such as cancer cells (5) and bacteria in the exponential growth phase (6).…”