BMC Microbiol 2010, 10:1.PubMedCrossRef”
“Retraction After lengthy investigation by the editors, the original article [1] has been retracted because of inappropriate duplication of images from previously published articles. The last author, Naoki Mori takes full responsibility and apologizes for any inconvenience caused. References 1. Takeshima E, Tomimori K, Kawakami Nutlin-3a in vivo H, Ishikawa C, Sawada S, Tomita M, Senba

M, Kinjo F, Minuro H, Sasakawa C, Fujita J, Mori N: NF-κB activation by Helicobacter pylori requires Akt-mediated phosphorylation of p65. BMC Microbiology 2009, 9:36.PubMedCrossRef”
“Background Bacteria, such as Escherichia coli, provide “”simple”" biological models due to a relatively small genome/proteome size (less than 5,000 genes/proteins) and are easy to culture. When the growth medium is rich in glucose, E. coli uses glycolysis to convert glucose into pyruvate, requiring adenosine diphosphate (ADP) and oxidized nicotinamide adenine dinucleotide (NAD+) as cofactors. But E. coli is also able to use many other sugars, including lactose, as the main carbon source [1]. The genetic mechanism of metabolic switch from glucose to lactose was first described Wortmannin in the

pioneering work of Jacob and Monod fifty years ago [2]. The operon model that they suggested [3] can be described as selleck chemicals follows: In the absence of any regulation, the expression of three structural genes (lacZ, lacY, lacA) is inhibited by a repressor molecule,

the protein product of lacI gene. If present, lactose is taken up from the medium and allolactose, formed from lactose, releases the repressor from the operator. In absence of glucose, selleck products cAMP concentration is high and cAMP binds to the catabolite activator protein (CAP), allowing the latter to bind to the promoter and initiate mRNA synthesis. This kind of double control causes the sequential utilization of the two sugars in discrete growth phases. According to this model, the operator region is not essential for operon activity, but rather serves as a controlling site superimposed on a functioning unit [4]. While previous studies were focused on discovery of genetic mechanisms of metabolic switches, we used a new label-free proteomic approach to study the dynamics of protein expression during the metabolic switch. Proteomics is a powerful and rapidly developing field of research, increasingly expanding our detailed understanding of biological systems. It can be used in basic studies on protein dynamics, localization, and function [5] but also to discover potential biomarkers for diseases and response to pharmaceuticals [6]. Proteomics aims to be comprehensive – quantifying “”all”" proteins present in an organism, tissue or cell. This is a non-trivial task, as there are no amplification methods akin to the polymerase chain reaction available, and proteins in a complex sample typically vary over many orders of magnitude in concentration.