2026-09-22T20:59:12Z https://www.ideals.illinois.edu/oai-pmh

oai:www.ideals.illinois.edu:2142/108081 2023-07-11 col_2142_5131 col_2142_16338 com_2142_5130 com_2142_16337 com_2142_14793 com_2142_8903

Vanderpool, Carin K Vanderpool, Carin K Cronan, John E Orlean, Peter A.B Metcalf, William W Bianco, Colleen Marion 2020-08-26T23:51:20Z 2020-08-26T23:51:20Z 2022-08-26T23:58:55Z 2020-01-23 2020-05 This project aims to understand the physiological role of the small RNA (sRNA) RydC and the signals controlling RydC production. RydC was previously shown to stabilize cfa (cyclopropane fatty acid synthase) mRNA, resulting in higher levels of cyclopropane fatty acids in the cell membrane. Here, we show that additional sRNAs, ArrS and CpxQ, also directly regulate cfa post-transcriptionally. RydC and ArrS act through masking an RNase E cleavage site in the cfa mRNA 5' untranslated region (UTR), and both sRNAs post-transcriptionally activate cfa. In contrast, CpxQ binds to a different site in the cfa mRNA 5' UTR and represses cfa expression in a mechanism that is dependent on Rho-mediated premature transcription termination. Alteration of membrane lipid composition is a key mechanism for bacteria to survive low pH environments, and we show that cfa translation increases in an sRNA-dependent manner when cells are subjected to mild acid stress. To further elucidate the physiological role of RydC, we sought to identify the transcription factor responsible for rydC expression. We demonstrate that the uncharacterized GntR family transcriptional regulator YieP represses transcription of the rydC in both Escherichia coli and Salmonella. We identify genes whose expression are dependent on YieP and determine that YieP may be playing a role regulating in amino acid transport, carbon metabolism, and aerobic respiration. We demonstrate that rydC transcription varies depending on the carbon source cells are utilizing. Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2022-05-01 The student, Colleen Bianco, accepted the attached license on 2020-01-22 at 10:27. The student, Colleen Bianco, submitted this Dissertation for approval on 2020-01-22 at 10:43. This Dissertation was approved for publication on 2020-01-23 at 09:43. DSpace SAF Submission Ingestion Package generated from Vireo submission #14855 on 2020-08-25 at 17:26:25 Made available in DSpace on 2020-08-26T23:51:20Z (GMT). No. of bitstreams: 2 BIANCO-DISSERTATION-2020.pdf: 24183901 bytes, checksum: 82417c3836269e2883796f6b4fc51e11 (MD5) LICENSE.txt: 4211 bytes, checksum: 6e1761f1a8d9e5bc6c55bf091b5fc9e5 (MD5) Previous issue date: 2020-01-23 Embargo set by: Seth Robbins for item 115690 Lift date: 2022-08-26T23:51:32Z Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD system Embargo set by: Seth Robbins for item 115690 Lift date: 2022-08-26T23:54:40Z Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD system Embargo set by: Seth Robbins for item 115690 Lift date: 2022-08-26T23:55:59Z Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD system Embargo set by: Seth Robbins for item 115690 Lift date: 2022-08-26T23:57:28Z Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD system Embargo set by: Seth Robbins for item 115690 Lift date: 2022-08-26T23:58:55Z Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD system Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD system U of I Only application/pdf http://hdl.handle.net/2142/108081 en Copyright 2020 Colleen M. Bianco Small RNA, Transcription Factors, Escherichia coli, Genetics, Genomics, Microbial Physiology, Protein-Nucleic Acid Interactions, Regulation of Gene Expression, RNA Biology, Signal Transduction Understanding the physiological role of the small RNA RydC text Thesis Microbiology Microbiology University of Illinois at Urbana-Champaign Dissertation Ph.D.