Heterologous expression of cyan and yellow fluorescent proteins from the Kluyveromyces lactis KlMAL21–KlMAL22 bi-directional promoter

Abstract

We have identified the Kluyveromyces lactis maltase (KlMAL22) and maltose permease (KlMAL21) intergenic region as a candidate bi-directional promoter for heterologous gene expression. The expressions of cyan and yellow fluorescent proteins from, respectively, the KlMAL22 and KlMAL21 orientations of the promoter, were compared between two promoter variants during growth in media containing glucose, galactose or glycerol. Expression from both orientations of the native promoter was repressed during growth in glucose and galactose and was induced during growth in glycerol. Disruption of a putative Mig1p binding site caused some de-repression of the maltase orientation of the promoter by 48 h of growth in glucose. The KlMAL21-KlMAL22 bi-directional promoter can be used to carry out regulated expression of heterologous gene products.

Genome Mining of Non-Conventional Yeasts: Search and Analysis of MAL Clusters and Proteins

“…In addition to Op and Opp , MAL clusters have been identified in some other non-conventional yeasts such as S. stipitis [ 21 ] and Kluyveromyces lactis [ 51 , 52 ] as well as in Aspergillus fungi [ 50 ]. In current study, MAL clusters of varied content, position, and number were detected in the genomes of L. elongisporus , Torulaspora delbrueckii , M. guillermondii , C. fabianii , D. hansenii , and Lipomyces starkeyi ( Figure 1 ) but not in B. adeninivorans and S. pombe .…”