De la Cruz Miguel Angel, Calva Edmundo
Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, México.
J Mol Microbiol Biotechnol. 2010;18(1):24-36. doi: 10.1159/000274309. Epub 2010 Jan 6.
Our understanding of porin regulation has revealed not only increasing complexity in the regulatory mechanisms, but also that the porin repertoire is more extensive than previously conceived. Initially, the OmpR response regulator was described as the master regulator of porin genes, but many more regulators are involved such as CpxR, PhoB, Lrp, Rob, MarA, SoxS, CadC, CRP, Fnr, ToxR, H-NS, StpA, IHF, HU and LeuO. In addition to MicF, the first small RNA (sRNA) that was proposed to regulate porin expression, porins are post-transcriptionally regulated by a variety of other sRNAs, namely, MicC, MicA, IpeX, RseX, InvR, CyaR and RybB. Future challenges include the full integration of all the regulatory circuitries. Whether quiescent porins are merely replacements of the major porins or are part of novel metabolic programs has yet to be elucidated. The comprehensive exploration of the environmental determinants that affect porin gene expression should yield valuable new information about the functions of these important proteins.
我们对孔蛋白调控的理解不仅揭示了调控机制日益复杂，还表明孔蛋白种类比之前设想的更为广泛。最初，OmpR应答调节蛋白被描述为孔蛋白基因的主要调节因子，但现在发现还有更多调节因子参与其中，如CpxR、PhoB、Lrp、Rob、MarA、SoxS、CadC、CRP、Fnr、ToxR、H-NS、StpA、IHF、HU和LeuO。除了最早提出的用于调节孔蛋白表达的小RNA（sRNA）MicF外，孔蛋白还受到多种其他sRNA的转录后调控，即MicC、MicA、IpeX、RseX、InvR、CyaR和RybB。未来的挑战包括全面整合所有调控通路。静态孔蛋白仅仅是主要孔蛋白的替代物，还是新型代谢程序的一部分，这还有待阐明。对影响孔蛋白基因表达的环境决定因素进行全面探索，应该会产生有关这些重要蛋白质功能的有价值新信息。
