Disease relevance of proP

• E. coli gene proP was isolated and located within a chromosomal DNA fragment [1].
• The slow growth of both pyelonephritis isolates in high-osmolality medium was stimulated by glycine betaine (GB) and deletion of proP and/or proU impaired GB uptake [2].

High impact information on proP

• Two full-length transporters could complement the Na(+)-sensitive phenotype of the Escherichia coli mutant deficient in betT, putPA, proP, and proU [3].
• That activity was: (i) dependent on the presence of the energy sources phenazine methosulphate plus ascorbate or D-lactate; (ii) observed only when a hyperosmotic shift accompanied the transport measurement; (iii) inhibited by glycine betaine in a manner analogous to that observed in whole cells; and (iv) eliminated by lesions in proP [4].
• The mRNA level of two genes was more than fivefold decreased in the mutant, i.e. betP and proP which encode transporters for the uptake of betaine and proline respectively [5].
• Transporters encoded in genetic loci putP, proP and proU mediate proline and/or betaine accumulation by Escherichia coli K-12 [1].
• Isolation and sequencing of Escherichia coli gene proP reveals unusual structural features of the osmoregulatory proline/betaine transporter, ProP [1].

Chemical compound and disease context of proP

• Under these conditions, an E. coli K-12 strain with lesions in both proP and proU accumulates low levels of L-carnitine but fails to accumulate betaine when these compounds are supplied in the external medium [6].
• Morpholinopropane sulfonic acid, a common constituent of microbiological media, accumulates in osmoadapting E. coli cells but it is not osmoprotective and it did not influence proP transcription or ProP activity [7].

Biological context of proP

• The lda region is part of a putative 26-kb genomic island inserted into the proP gene of the E. coli chromosome [8].

Anatomical context of proP

• Deletion of proP and proU slowed the growth of E. coli HU734 in this high-osmolality human urine (which contains betaines) but had little impact on its colonization of the murine urinary tract after transurethral inoculation [2].

Associations of proP with chemical compounds

• In vitro expression of proP yielded a protein whose apparent molecular mass was determined to be 42 kDa by polyacrylamide gel electrophoresis under denaturing conditions [1].
• Protein purification was facilitated by the addition of six histidine (His) codons to the 3' end of proP [9].
• An HU734 derivative lacking both proP and proU retained osmoprotective GB uptake activity that could be attributed to system BetU, which is not present in strain K-12 or CFT073 [2].
• We find that proP, which encodes a low-affinity transporter of the important osmoprotectants proline and glycine betaine, is transcribed from two promoters. proP1 is transiently induced upon subculture and is upregulated by increases in medium osmolarity [10].

Other interactions of proP

• By contrast, deletion of rpoS, proP and proU had no effect on the very rapid growth of CFT073 in high-osmolality urine or on its experimental colonization of the murine urinary tract [2].
• In the presence of Fis, proP2 expression is increased over 50-fold, as judged by the LacZ activity of cells carrying the proP-lacZ fusion as well as by direct RNA analysis, making this the most strongly activated promoter by Fis that has been described [10].

References