Dissecting the role of the two Streptomyces peucetius var. caesius glucokinases in the sensitivity to carbon catabolite repression

Abstract

Streptomyces peucetius var. caesius, the doxorubicin-producing strain, has two glucokinases (Glk) for glucose phosphorylation. One of them (ATP-Glk) uses adenosine triphosphate as its phosphate source, and the other one uses polyphosphate (PP). Glk regulates the carbon catabolite repression (CCR) process, as well as glucose utilization. However, in the streptomycetes, the specific role of each one of the Glks in these processes is unknown. With the use of PP- and ATP-Glk null mutants, we aimed to establish their respective role in glucose metabolism and their possible implication in the CCR. Our results supported that in S. peucetius var. caesius, both Glks allowed this strain to grow in different glucose concentrations. PP-Glk seems to be the main enzyme for glucose metabolism, and ATP-Glk is the only one involved in the CCR process affecting the levels of α-amylase and anthracycline production. Besides, analysis of Glk activities in the parental strain and the mutants revealed ATP-Glk as an enzyme negatively affected by high glucose concentrations. Although ATP-Glk utilizes only ATP as the substrate for glucose phosphorylation, probably PP-Glk can use either ATP or polyphosphate. Finally, a possible connection between both Glks may exist from the regulatory point of view.

An overview of the two-component system GarR/GarS role on antibiotic production in Streptomyces coelicolor

“…The WT strain and its derived mutants are available at the UNAM-48/WFCC (Mexico City). All Streptomyces strains were stored as spore suspensions in 20% (v/v) glycerol at − 20 °C as previously described (Rocha-Mendoza et al 2021 ). Gene disruption was performed by PCR-targeting with the cosmid St1A9, E .…”

“…The effect of the carbon source on the synthesis of secondary metabolites has been extensively studied in Streptomyces (Romero-Rodríguez et al 2016a ; Guzmán et al 2005 ; Gubbens et al 2012 ; Magdalena et al 2012 ; Tierrafría et al 2016 ), which is regulated by a mechanism known as carbon catabolite repression (CCR) (Ruiz-Villafán et al 2021 ). Although glucose and the glucose kinase (Glk) are the most studied factors influencing this regulatory process in S. coelicolor , nowadays, its precise mechanism is still poorly understood (Ruiz-Villafán et al 2021 ; Angell et al 1994 ; Rocha-Mendoza et al 2021 ). Glucose, a carbon source commonly used under laboratory conditions, promotes the rapid growth of Streptomyces and, at the same time, represses the synthesis of secondary metabolites (Romero-Rodríguez et al 2018 ; Guzmán et al 2005 ; Tierrafría et al 2016 ).…”