Study of Cryptococcus neoformans actin gene regulation with a beta-galactosidase-actin fusion.

Journal Article (Journal Article)

An expression plasmid carrying a heterologous gene fusion between the Cryptococcus neoformans actin promoter and the Escherichia coli reporter gene, LACZ, was constructed to study actin regulation in C. neoformans. Two randomly stable transformants, designated 20.6 and 20.9, were selected for further examination. Both ectopic and homologous recombination with vector insertion in tandem repeats occurred in these transformants. Transformant 20.9 carried more copies of ACTp::LACZ in its genome than 20.6 and this was reflected in expressing higher levels of beta-galactosidase activity. In vitro, these transformants showed higher levels of beta-galactosidase activity expressed when the transformants were propagated at higher temperatures (37 degrees C vs 30 degrees C). However, beta-galactosidase expression in the transformants was variable during logarithmic and stationary growth phases and this differential expression was temperature dependent. This report shows that the constitutive actin gene in C. neoformans is regulated by temperature and growth and this fact should be taken into consideration when actin expression is used as a standard to compare the expression of other regulated genes. Also, a more sensitive reporter construct will be needed for in vivo gene analysis of regulation.

Full Text

Duke Authors

Cited Authors

  • Toffaletti, DL; Perfect, JR

Published Date

  • 1997

Published In

Volume / Issue

  • 35 / 5

Start / End Page

  • 313 - 320

PubMed ID

  • 9402523

International Standard Serial Number (ISSN)

  • 0268-1218


  • eng

Conference Location

  • England