title: Eukaryote-like Ser/Thr protein kinase PrkA modulates sporulation via regulating the transcriptional factor σ(K) in Bacillus subtilis.
abstract: Protein kinase A (PrkA), also known as AMP-activated protein kinase, functions as a serine/threonine protein kinase (STPK), has been shown to be involved in a variety of important biologic processes, including pathogenesis of many important diseases in mammals. However, the biological functions of PrkA are less known in prokaryote cells. Here, we explored the function of PrkA as well as its underlying molecular mechanisms using the model bacterium Bacillus subtilis168. When PrkA is inhibited by 9-β-D-arabinofuranosyladenine (ara-A) in the wild type strain or deleted in the ΔprkA mutant strain, we observed sporulation defects in B. subtilis 168, suggesting that PrkA functions as a sporulation-related protein. Transcriptional analysis using the lacZ reporter gene demonstrated that deletion of prkA significantly reduced the expression of the transcriptional factor σ(K) and its downstream genes. Complementation of sigK gene in prkA knockout mutant partially rescued the phenotype of ΔprkA, further supporting the hypothesis that the decreased σ(K) expression should be one of the reasons for the sporulation defect resulting from prkA disruption. Finally, our data confirmed that Hpr (ScoC) negatively controlled the expression of transcriptional factor σ(K), and thus PrkA accelerated sporulation and the expression of σ(K) by suppression of Hpr (ScoC). Taken together, our study discovered a novel function of the eukaryotic-like STPK PrkA in spore development as well as its underlying molecular mechanism in B. subtilis.
authors.affiliation: Laboratory for Conservation and Utilization of Bio-Resources, and Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University Kunming, China.
authors.forename: Jinyuan
authors.initials: J
authors.lastname: Yan
authors.affiliation: Laboratory for Conservation and Utilization of Bio-Resources, and Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University Kunming, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Zou
authors.affiliation: Laboratory for Conservation and Utilization of Bio-Resources, and Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University Kunming, China.
authors.forename: Juan
authors.initials: J
authors.lastname: Fang
authors.affiliation: Laboratory for Conservation and Utilization of Bio-Resources, and Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University Kunming, China.
authors.forename: Xiaowei
authors.initials: X
authors.lastname: Huang
authors.affiliation: Laboratory for Conservation and Utilization of Bio-Resources, and Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University Kunming, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Gao
authors.affiliation: Laboratory for Conservation and Utilization of Bio-Resources, and Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University Kunming, China.
authors.forename: Zeying
authors.initials: Z
authors.lastname: He
authors.affiliation: Laboratory for Conservation and Utilization of Bio-Resources, and Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University Kunming, China.
authors.forename: Keqin
authors.initials: K
authors.lastname: Zhang
authors.affiliation: Department of Neurosurgery, The Second Affiliated Hospital of Kunming Medical College Kunming, China.
authors.forename: Ninghui
authors.initials: N
authors.lastname: Zhao
keywords: B. subtilis; PrkA; serine/threonine protein kinase; sporulation; the transcription factor σK; transcriptional regulation