ГЕМОРРАГИИ /хирГЕМОСТАЗ ЭНДОСКОПИЧЕСКИЙПЕПТИЧЕСКАЯ ЯЗВА /хи

Caroline Bäreclev (683823)

Jörgen Johansson (458315)

Karolis Vaitkevicius (257327)

Sakura Netterling (683824)

PubMed

RNA-helicases are proteins required for the unwinding of occluding secondary RNA structures, especially at low temperatures. In this work, we have deleted all 4 DExD-box RNA helicases in various combinations in the Gram-positive pathogen Listeria monocytogenes. Our results show that 3 out of 4 RNA-helicases were important for growth at low temperatures, whereas the effect was less prominent at 37 degrees C. Over-expression of one RNA-helicase, Lmo1450, was able to overcome the reduced growth of the quadruple mutant strain at temperatures above 26 degrees C, but not at lower temperatures. The maturation of ribosomes was affected in different degrees in the various strains at 20 degrees C, whereas the effect was marginal at 37 degrees C. This was accompanied by an increased level of immature 23S rRNA precursors in some of the RNA-helicase mutants at low temperatures. Although the expression of the PrfA regulated virulence factors ActA and LLO decreased in the quadruple mutant strain, this strain showed a slightly increased infection ability. Interestingly, even though the level of the virulence factor LLO was decreased in the quadruple mutant strain as compared with the wild-type strain, the hly-transcript (encoding LLO) was increased. Hence, our results could suggest a role for the RNA-helicases during translation. In this work, we show that DExD-box RNA-helicases are involved in bacterial virulence gene-expression and infection of eukaryotic cells

Bäreclev, Caroline

Vaitkevicius, Karolis

Netterling, Sakura

Johansson, Jörgen

Publikationer från Umeå universitet

DExD-box RNA-helicases in Listeria monocytogenes are important for growth, ribosomal maturation, rRNA processing and virulence factor expression

Academic Archive On-line (Umeå University, Sweden)

<div><p>RNA-helicases are proteins required for the unwinding of occluding secondary RNA structures, especially at low temperatures. In this work, we have deleted all 4 DExD-box RNA helicases in various combinations in the Gram-positive pathogen <i>Listeria monocytogenes</i>. Our results show that 3 out of 4 RNA-helicases were important for growth at low temperatures, whereas the effect was less prominent at 37°C. Over-expression of one RNA-helicase, Lmo1450, was able to overcome the reduced growth of the quadruple mutant strain at temperatures above 26°C, but not at lower temperatures. The maturation of ribosomes was affected in different degrees in the various strains at 20°C, whereas the effect was marginal at 37°C. This was accompanied by an increased level of immature 23S rRNA precursors in some of the RNA-helicase mutants at low temperatures. Although the expression of the PrfA regulated virulence factors ActA and LLO decreased in the quadruple mutant strain, this strain showed a slightly increased infection ability. Interestingly, even though the level of the virulence factor LLO was decreased in the quadruple mutant strain as compared with the wild-type strain, the <i>hly</i>-transcript (encoding LLO) was increased. Hence, our results could suggest a role for the RNA-helicases during translation. In this work, we show that DExD-box RNA-helicases are involved in bacterial virulence gene-expression and infection of eukaryotic cells.</p></div

FigShare

DExD-box RNA-helicases in <i>Listeria monocytogenes</i> are important for growth, ribosomal maturation, rRNA processing and virulence factor expression

Ларичев, А. Б.

Фавстов, С. В.

Бахилина, В. Л.

Electronic arhive of Vitebsk State Medical University Library  (Репозиторий библиотеки Витебского государственного медицинского университета)