Polyamine synthesis and interconversion by the microsporidian Encephalitozoon cuniculi

Cyrus J. Bacchi, Schennella Lane, Louis M. Weiss, Nigel Yarlett, Peter Takvorian, Murray Wittner

Research output: Contribution to journalArticle

12 Citations (Scopus)

Abstract

Polyamines are small cationic molecules necessary for growth and differentiation in all cells. Although mammalian cells have been studied extensively, particularly as targets of polyamine antagonists, i.e. antitumor agents, polyamine metabolism has also been studied as a potential drug target in microorganisms. Since little is known concerning polyamine metabolism in the microsporidia, we investigated it in Encephalitozoon cuniculi, a microsporidian associated with disseminated infections in humans. Organisms were grown in RK-13 cells and harvested using Percoll gradients. Electron microscopy indicated that the fractions banding at 1.051-1.059/ g/ml in a microgradient procedure, and 1.102-1.119/g/ml in a scaled-up procedure were nearly homogenous, consisting of pre-emergent (immature) spores which showed large arrays of ribosomes near polar filament coils. Intact purified pre-emergent spores incubated with [3H] ornithine and methionine synthesized putrescine, spermidine, and spermine, while [14C]spermine was converted to spermidine and putrescine. Polyamine production from ornithine was inhibitable by DL-α-difluoromethylornithine (DFMO) but not by DL-α-difluoromethylarginine (DFMA). Cell-free extracts from mature spores released into the growth media had ornithine decarboxylase (ODC), Sadenosylmethionine decarboxylase (AdoMetdc), and spermidine/spermine N1-acetyltransferase (SSAT) activities. ODC activity was inhibited by DFMO, but not by DFMA. AdoMetdc was putrescine-stimulated and inhibited by methylglyoxal-bis(guanylhydrazone); arginine decarboxylase activity could not be detected. It is apparent from these studies that Encephalitozoon cuniculi pre-emergent spores have a eukaryotic-type polyamine biosynthetic pathway and can interconvert exogenous polyamines. Pre-emergent spores were metabolically active with respect to polyamine synthesis and interconversion, while intact mature spores harvested from culture supernatants had little metabolic activity.

Original languageEnglish (US)
Pages (from-to)374-381
Number of pages8
JournalJournal of Eukaryotic Microbiology
Volume48
Issue number3
StatePublished - 2001

Fingerprint

Encephalitozoon cuniculi
Microsporidia
Polyamines
polyamines
Spores
synthesis
spores
Putrescine
Spermine
spermine
spermidine
putrescine
Eflornithine
ornithine decarboxylase
Ornithine
Ornithine Decarboxylase
Spermidine
ornithine
Mitoguazone
cells

Keywords

  • Microsporidia
  • Percoll gradient
  • Polyamine metabolism
  • Protozoa

ASJC Scopus subject areas

  • Agricultural and Biological Sciences(all)
  • Applied Microbiology and Biotechnology
  • Agricultural and Biological Sciences (miscellaneous)
  • Microbiology

Cite this

Bacchi, C. J., Lane, S., Weiss, L. M., Yarlett, N., Takvorian, P., & Wittner, M. (2001). Polyamine synthesis and interconversion by the microsporidian Encephalitozoon cuniculi. Journal of Eukaryotic Microbiology, 48(3), 374-381.

Polyamine synthesis and interconversion by the microsporidian Encephalitozoon cuniculi. / Bacchi, Cyrus J.; Lane, Schennella; Weiss, Louis M.; Yarlett, Nigel; Takvorian, Peter; Wittner, Murray.

In: Journal of Eukaryotic Microbiology, Vol. 48, No. 3, 2001, p. 374-381.

Research output: Contribution to journalArticle

Bacchi, CJ, Lane, S, Weiss, LM, Yarlett, N, Takvorian, P & Wittner, M 2001, 'Polyamine synthesis and interconversion by the microsporidian Encephalitozoon cuniculi', Journal of Eukaryotic Microbiology, vol. 48, no. 3, pp. 374-381.
Bacchi, Cyrus J. ; Lane, Schennella ; Weiss, Louis M. ; Yarlett, Nigel ; Takvorian, Peter ; Wittner, Murray. / Polyamine synthesis and interconversion by the microsporidian Encephalitozoon cuniculi. In: Journal of Eukaryotic Microbiology. 2001 ; Vol. 48, No. 3. pp. 374-381.
@article{2f7a90919bca40209926770043482b04,
title = "Polyamine synthesis and interconversion by the microsporidian Encephalitozoon cuniculi",
abstract = "Polyamines are small cationic molecules necessary for growth and differentiation in all cells. Although mammalian cells have been studied extensively, particularly as targets of polyamine antagonists, i.e. antitumor agents, polyamine metabolism has also been studied as a potential drug target in microorganisms. Since little is known concerning polyamine metabolism in the microsporidia, we investigated it in Encephalitozoon cuniculi, a microsporidian associated with disseminated infections in humans. Organisms were grown in RK-13 cells and harvested using Percoll gradients. Electron microscopy indicated that the fractions banding at 1.051-1.059/ g/ml in a microgradient procedure, and 1.102-1.119/g/ml in a scaled-up procedure were nearly homogenous, consisting of pre-emergent (immature) spores which showed large arrays of ribosomes near polar filament coils. Intact purified pre-emergent spores incubated with [3H] ornithine and methionine synthesized putrescine, spermidine, and spermine, while [14C]spermine was converted to spermidine and putrescine. Polyamine production from ornithine was inhibitable by DL-α-difluoromethylornithine (DFMO) but not by DL-α-difluoromethylarginine (DFMA). Cell-free extracts from mature spores released into the growth media had ornithine decarboxylase (ODC), Sadenosylmethionine decarboxylase (AdoMetdc), and spermidine/spermine N1-acetyltransferase (SSAT) activities. ODC activity was inhibited by DFMO, but not by DFMA. AdoMetdc was putrescine-stimulated and inhibited by methylglyoxal-bis(guanylhydrazone); arginine decarboxylase activity could not be detected. It is apparent from these studies that Encephalitozoon cuniculi pre-emergent spores have a eukaryotic-type polyamine biosynthetic pathway and can interconvert exogenous polyamines. Pre-emergent spores were metabolically active with respect to polyamine synthesis and interconversion, while intact mature spores harvested from culture supernatants had little metabolic activity.",
keywords = "Microsporidia, Percoll gradient, Polyamine metabolism, Protozoa",
author = "Bacchi, {Cyrus J.} and Schennella Lane and Weiss, {Louis M.} and Nigel Yarlett and Peter Takvorian and Murray Wittner",
year = "2001",
language = "English (US)",
volume = "48",
pages = "374--381",
journal = "Journal of Eukaryotic Microbiology",
issn = "1066-5234",
publisher = "Wiley-Blackwell",
number = "3",

}

TY - JOUR

T1 - Polyamine synthesis and interconversion by the microsporidian Encephalitozoon cuniculi

AU - Bacchi, Cyrus J.

AU - Lane, Schennella

AU - Weiss, Louis M.

AU - Yarlett, Nigel

AU - Takvorian, Peter

AU - Wittner, Murray

PY - 2001

Y1 - 2001

N2 - Polyamines are small cationic molecules necessary for growth and differentiation in all cells. Although mammalian cells have been studied extensively, particularly as targets of polyamine antagonists, i.e. antitumor agents, polyamine metabolism has also been studied as a potential drug target in microorganisms. Since little is known concerning polyamine metabolism in the microsporidia, we investigated it in Encephalitozoon cuniculi, a microsporidian associated with disseminated infections in humans. Organisms were grown in RK-13 cells and harvested using Percoll gradients. Electron microscopy indicated that the fractions banding at 1.051-1.059/ g/ml in a microgradient procedure, and 1.102-1.119/g/ml in a scaled-up procedure were nearly homogenous, consisting of pre-emergent (immature) spores which showed large arrays of ribosomes near polar filament coils. Intact purified pre-emergent spores incubated with [3H] ornithine and methionine synthesized putrescine, spermidine, and spermine, while [14C]spermine was converted to spermidine and putrescine. Polyamine production from ornithine was inhibitable by DL-α-difluoromethylornithine (DFMO) but not by DL-α-difluoromethylarginine (DFMA). Cell-free extracts from mature spores released into the growth media had ornithine decarboxylase (ODC), Sadenosylmethionine decarboxylase (AdoMetdc), and spermidine/spermine N1-acetyltransferase (SSAT) activities. ODC activity was inhibited by DFMO, but not by DFMA. AdoMetdc was putrescine-stimulated and inhibited by methylglyoxal-bis(guanylhydrazone); arginine decarboxylase activity could not be detected. It is apparent from these studies that Encephalitozoon cuniculi pre-emergent spores have a eukaryotic-type polyamine biosynthetic pathway and can interconvert exogenous polyamines. Pre-emergent spores were metabolically active with respect to polyamine synthesis and interconversion, while intact mature spores harvested from culture supernatants had little metabolic activity.

AB - Polyamines are small cationic molecules necessary for growth and differentiation in all cells. Although mammalian cells have been studied extensively, particularly as targets of polyamine antagonists, i.e. antitumor agents, polyamine metabolism has also been studied as a potential drug target in microorganisms. Since little is known concerning polyamine metabolism in the microsporidia, we investigated it in Encephalitozoon cuniculi, a microsporidian associated with disseminated infections in humans. Organisms were grown in RK-13 cells and harvested using Percoll gradients. Electron microscopy indicated that the fractions banding at 1.051-1.059/ g/ml in a microgradient procedure, and 1.102-1.119/g/ml in a scaled-up procedure were nearly homogenous, consisting of pre-emergent (immature) spores which showed large arrays of ribosomes near polar filament coils. Intact purified pre-emergent spores incubated with [3H] ornithine and methionine synthesized putrescine, spermidine, and spermine, while [14C]spermine was converted to spermidine and putrescine. Polyamine production from ornithine was inhibitable by DL-α-difluoromethylornithine (DFMO) but not by DL-α-difluoromethylarginine (DFMA). Cell-free extracts from mature spores released into the growth media had ornithine decarboxylase (ODC), Sadenosylmethionine decarboxylase (AdoMetdc), and spermidine/spermine N1-acetyltransferase (SSAT) activities. ODC activity was inhibited by DFMO, but not by DFMA. AdoMetdc was putrescine-stimulated and inhibited by methylglyoxal-bis(guanylhydrazone); arginine decarboxylase activity could not be detected. It is apparent from these studies that Encephalitozoon cuniculi pre-emergent spores have a eukaryotic-type polyamine biosynthetic pathway and can interconvert exogenous polyamines. Pre-emergent spores were metabolically active with respect to polyamine synthesis and interconversion, while intact mature spores harvested from culture supernatants had little metabolic activity.

KW - Microsporidia

KW - Percoll gradient

KW - Polyamine metabolism

KW - Protozoa

UR - http://www.scopus.com/inward/record.url?scp=0035009623&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0035009623&partnerID=8YFLogxK

M3 - Article

VL - 48

SP - 374

EP - 381

JO - Journal of Eukaryotic Microbiology

JF - Journal of Eukaryotic Microbiology

SN - 1066-5234

IS - 3

ER -