Environmental control of the in vivo oligomerization of nucleoid protein H-NS

TY - JOUR

T1 - Environmental control of the in vivo oligomerization of nucleoid protein H-NS

AU - Stella, Stefano

AU - Falconi, Maurizio

AU - Lammi, Matilde

AU - Gualerzi, Claudio O.

AU - Pon, Cynthia L.

PY - 2006/1/13

Y1 - 2006/1/13

N2 - The nucleoid-associated transcriptional repressor H-NS forms both dimers and tetramers in vivo. Two types of two-hybrid systems, one capable of detecting protein dimerization and the other protein tetramerization, have been used to determine whether environmental changes could affect the oligomerization capacity of this protein in the cell. Increasing the temperature from 37°C to 48°C and changing the pH between 4.0 and 9.0 did not influence either dimerization or tetramerization, whereas lowering the temperature below 25°C and increasing osmolarity were found to reduce the formation of H-NS tetramers, which are the active form of this protein, without affecting dimerization. These findings provide a rationale to explain the induction of H-NS expression during cold-shock, suggest a mechanism contributing to derepressing osmotic-shock genes transcriptionally regulated by H-NS and indicate that changes of the oligomerization properties of H-NS do not play a role in the H-NS and temperature-dependent control of virulence gene expression.

AB - The nucleoid-associated transcriptional repressor H-NS forms both dimers and tetramers in vivo. Two types of two-hybrid systems, one capable of detecting protein dimerization and the other protein tetramerization, have been used to determine whether environmental changes could affect the oligomerization capacity of this protein in the cell. Increasing the temperature from 37°C to 48°C and changing the pH between 4.0 and 9.0 did not influence either dimerization or tetramerization, whereas lowering the temperature below 25°C and increasing osmolarity were found to reduce the formation of H-NS tetramers, which are the active form of this protein, without affecting dimerization. These findings provide a rationale to explain the induction of H-NS expression during cold-shock, suggest a mechanism contributing to derepressing osmotic-shock genes transcriptionally regulated by H-NS and indicate that changes of the oligomerization properties of H-NS do not play a role in the H-NS and temperature-dependent control of virulence gene expression.

KW - Environmental control

KW - Protein dimerization and tetramerization

KW - Transcriptional repression

KW - Two-hybrid system

UR - http://www.scopus.com/inward/record.url?scp=28844491363&partnerID=8YFLogxK

U2 - 10.1016/j.jmb.2005.10.034

DO - 10.1016/j.jmb.2005.10.034

M3 - Journal article

C2 - 16303134

AN - SCOPUS:28844491363

SN - 0022-2836

VL - 355

SP - 169

EP - 174

JO - Journal of Molecular Biology

JF - Journal of Molecular Biology

IS - 2

ER -