title: Analysis of host-inducing proteome changes in bifidobacterium longum NCC2705 grown in Vivo.
abstract: To investigate the molecular mechanisms underlying the adaptation of Bifidobacterium longum to the intestinal tract, we utilized a new model for rabbit intestinal culture of B. longum and reported the changes in proteomic profiles after incubation in the in vivo environment. By 2D-PAGE coupled with matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and/or electrospray ionization tandem mass spectrometry (ESI-MS/MS) analyses, proteomic profiles of B. longum strain NCC2705 grown in the in vivo and in vitro environments were compared. Confirmed by semiquantitative RT-PCR, which exhibited at least a 3-fold change or greater, 19 up-regulated proteins, 14 down-regulated proteins, and 4 proteins with mobility changes were identified during intestinal growth. These identified proteins include key stress proteins, metabolism-related proteins, and proteins related to translation. Our results indicate that some useful proteins are expressed at higher levels in cells during intestinal growth. These proteins reflected the adaptation of B. longum NCC2705 to the intestine, such as EF-Tu which contributes to the retention or attachment as a Bifidobacterium adhesin-like factor, bile salt hydrolase (BSH) which might play an important role in the molecular mechanisms for the initial interaction of probiotic with the intestinal environment, and stress proteins which defend B. longum against the action of bile salts and other harmful ingredients of the gastrointestinal tract (GIT). The most striking fact of our observation was that four proteins GlnA1, PurC, LuxS, and Pgk exhibit clear post-translational modification. Western blot (WB) analysis and Pro-Q Diamond staining revealed that substances of the GIT trigger Pgk and LuxS phosphorylation at Ser/Thr residues for bacteria grown in vivo. These proteins were identified for the first time as bifidobacterial phosphoproteins. Our data suggest that the phosphorylated autoinducer-2 production protein LuxS of B. longum NCC2705 (LuxS-P) is the active form of LuxS and that LuxS-P may play a key role in the regulation of quorum sensing.
authors.affiliation: Institute of Disease Control and Prevention, Academy of Military Medical Sciences, Beijing, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Yuan
authors.forename: Bin
authors.initials: B
authors.lastname: Wang
authors.forename: Zhongke
authors.initials: Z
authors.lastname: Sun
authors.forename: Xin
authors.initials: X
authors.lastname: Bo
authors.forename: Xitong
authors.initials: X
authors.lastname: Yuan
authors.forename: Xiang
authors.initials: X
authors.lastname: He
authors.forename: Hongqing
authors.initials: H
authors.lastname: Zhao
authors.forename: Xinying
authors.initials: X
authors.lastname: Du
authors.forename: Fang
authors.initials: F
authors.lastname: Wang
authors.forename: Zheng
authors.initials: Z
authors.lastname: Jiang
authors.forename: Ling
authors.initials: L
authors.lastname: Zhang
authors.forename: Leili
authors.initials: L
authors.lastname: Jia
authors.forename: Yufei
authors.initials: Y
authors.lastname: Wang
authors.forename: Kaihua
authors.initials: K
authors.lastname: Wei
authors.forename: Jie
authors.initials: J
authors.lastname: Wang
authors.forename: Xuemin
authors.initials: X
authors.lastname: Zhang
authors.forename: Yansong
authors.initials: Y
authors.lastname: Sun
authors.forename: Liuyu
authors.initials: L
authors.lastname: Huang
authors.forename: Ming
authors.initials: M
authors.lastname: Zeng
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics*; D000818:Animals; D001644:Bifidobacterium / Q000737:chemistry / Q000235:genetics* / Q000502:physiology; D015536:Down-Regulation; D015180:Electrophoresis, Gel, Two-Dimensional; D020869:Gene Expression Profiling; D007422:Intestines / Q000382:microbiology*; D020543:Proteome / Q000032:analysis* / Q000235:genetics; D040901:Proteomics / Q000379:methods; D053038:Quorum Sensing / Q000235:genetics; D011817:Rabbits; D053719:Tandem Mass Spectrometry; D015854:Up-Regulation
chemical_list: D020543:Proteome