High impact information on MAL11

• Analysis of the MTP1 gene and its translation product mtTBP may provide an insight into the evolutionary origin of linear mitochondrial genomes and the role it plays in their replication and maintenance [1].
• AGT1 expression is maltose inducible and induction is mediated by the Mal-activator [2].
• Like Mal61p, Agt1p is a high-affinity, maltose/proton symporter, but Mal61p is capable of transporting only maltose and turanose, while Agt1p transports these two alpha-glucosides as well as several others including isomaltose, alpha-methylglucoside, maltotriose, palatinose, trehalose and melezitose [2].
• Molecular genetic analysis is used to characterize the AGT1 gene encoding an alpha-glucoside transporter [2].
• The sequence of the upstream region of AGT1 is identical to that of the maltose-inducible MAL61 gene over a 469 bp region containing the UASMAL but the 315 bp sequence immediately upstream of AGT1 shows no significant homology to the sequence immediately upstream of MAL61 [2].

Biological context of MAL11

• Four different MAL genotypes were observed with MAL11 and MAL31 predominating [3].
• Homologues of AGT1 were identified in three of the lager strains, and two of these homologues were mapped, one to chromosome II and the other to chromosome XI [4].
• We also found that Agt1p-mediated trehalose transport and the hydrolysis of the disaccharide by the cytosolic neutral trehalase Nth1p are coupled and represent a second, independent pathway, although there are several constraints on this alternative route [5].
• Maltose transport by two ale strains was strongly inhibited by other alpha-glucosides, suggesting the use of broad substrate specificity transporters, such as Agt1p [6].
• By complementing this strain with permeases encoded by MAL31, MAL61, and AGT1, it was possible to measure their specific transport kinetics by using maltotriose and maltose [7].

Anatomical context of MAL11

• Our results show that pNPalphaG is actively transported by S. cerevisiae cells by a H+-symport mechanism, which depends on the electrochemical proton gradient across the plasma membrane. pNPalphaG uptake is mediated by the AGT1 alpha-glucoside permease, which has a high affinity (Km=3 mM) for this chromogenic substrate [8].

Associations of MAL11 with chemical compounds

• In contrast, expression of the maltose permease gene (MAL11) and maltose utilization is normal [9].
• Our results indicate that the maltose-H+ symporters encoded by MAL11, MAL21, and MAL41 are not responsible for the trehalose transport activity [10].
• In a yeast strain deleted for HXT1-17, GAL2, AGT1, YDL247w and YJR160c, glucose consumption and transport activity were completely abolished [11].
• Maltotriose utilization from the permease encoded by AGT1 was regulated by the same genetic mechanisms as those involving the maltose transcriptional activator [7].
• We show here that MAL64c has in addition pleiotropic effects on sugar fermentation: MAL64c strains constitutively synthesize an alpha-methylglucosidase and can complement a new gene, MTP1, for the fermentation of melezitose and alpha-methylglucoside [12].

Other interactions of MAL11

• However, expression of Mty1p restores growth of the S. cerevisiae receptor strain on both maltose and maltotriose, whereas the closely related Mal31p supports growth on maltose only and Agt1p supports growth on a wider range of substrates, including maltose and maltotriose [13].
• Known pleiotropic genes PDR5 and MAL11 are more accurately represented by the model than by a clustering procedure that requires genes to belong to a single cluster [14].
• Evidence is presented that these two classes of mutants identify both a gene involved in the regulation of maltose identify both a gene involved in the regulation of maltose fermentation (MAL1R) and a gene involved in maltose transport (MAL1T) [15].

References