Role of catabolite control protein A in the regulation of intermedilysin production by Streptococcus intermedius.

نویسندگان

  • Toshifumi Tomoyasu
  • Atsushi Tabata
  • Riki Hiroshima
  • Hidenori Imaki
  • Sachiko Masuda
  • Robert A Whiley
  • Joseph Aduse-Opoku
  • Ken Kikuchi
  • Keiichi Hiramatsu
  • Hideaki Nagamune
چکیده

Streptococcus intermedius is an opportunistic pathogen of humans that causes purulent infections, including brain and liver abscesses. This pathogen secretes a human-specific cytolysin, intermedilysin, which has been recognized as a major virulence factor. However, most of the expressional control mechanisms of ily are still unknown. To determine these mechanisms, we analyzed the nucleotide sequence of the ily promoter region. We found a highly homologous region to the catabolite-repressible element (cre) in the ily promoter region and observed a considerable decrease in the amount of secreted intermedilysin when cells were grown in a culture medium containing high concentrations of glucose/utilizable carbohydrates. Disruption of the ccpA gene, which encodes catabolite control protein A, did not induce catabolite repression of ily by glucose/utilizable carbohydrates. In cre mutants, catabolite repression of ily was partially restored, and purified catabolite control protein A bound to an oligonucleotide containing the cre consensus sequence in the ily promoter region. In addition, a prolonged lag phase and slower doubling time of the ccpA mutant cells were observed. Our data show that S. intermedius can modulate ily expression and growth rate through catabolite control protein A-mediated monitoring of the extracellular glucose/utilizable carbohydrate concentration.

برای دانلود رایگان متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Investigation of a bacterial pore-forming chimera toxin for application as a novel drug-delivery system tool.

BACKGROUND/AIM Cholesterol-dependent cytolysins (CDCs) are pore-forming toxins from Gram-positive bacteria. The aim of this study was to investigate the potential of a CDC, intermedilysin, as a drug-delivery system (DDS) for clinical application. MATERIALS AND METHODS Intermedilysin was modified by the addition of a disulfide bridge to regulate pore formation, by swapping domain 4 to provide ...

متن کامل

The Cytolytic Activity of Vaginolysin Strictly Depends on Cholesterol and Is Potentiated by Human CD59

Gardnerella vaginalis produces cytolysin vaginolysin (VLY), which has been suggested to be a contributor to bacterial vaginosis pathogenesis. VLY along with intermedilysin (ILY) from Streptococcus intermedius have been attributed to a group of cholesterol-dependent cytolysins (CDCs) whose pore-forming activity depends on human CD59 (hCD59). Here, we show that different types of cells lacking hC...

متن کامل

Structural Basis for Recognition of the Pore-Forming Toxin Intermedilysin by Human Complement Receptor CD59

Pore-forming proteins containing the structurally conserved membrane attack complex/perforin fold play an important role in immunity and host-pathogen interactions. Intermedilysin (ILY) is an archetypal member of a cholesterol-dependent cytolysin subclass that hijacks the complement receptor CD59 to make cytotoxic pores in human cells. ILY directly competes for the membrane attack complex bindi...

متن کامل

Molecular dynamics of human-specific cytolysin: analysis of membrane binding motif for therapeutic application.

BACKGROUND Intermedilysin (ILY) is a human-specific cytolysin secreted from Streptococcus intermedius. In this study, the dynamic structure of ILY, StreptolysinO (SLO) and their 12mer substituted mutants for 500 ps was analyzed. Several parameters, such as dipole moment and electrostatic potential, were determined to elucidate the molecular mechanism of membrane binding. MATERIALS AND METHODS...

متن کامل

Disentangling the roles of cholesterol and CD59 in intermedilysin pore formation

The plasma membrane provides an essential barrier, shielding a cell from the pressures of its external environment. Pore-forming proteins, deployed by both hosts and pathogens alike, breach this barrier to lyse target cells. Intermedilysin is a cholesterol-dependent cytolysin that requires the human immune receptor CD59, in addition to cholesterol, to form giant β-barrel pores in host membranes...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

عنوان ژورنال:
  • Infection and immunity

دوره 78 9  شماره 

صفحات  -

تاریخ انتشار 2010