Disease relevance of MAL12

• The recombinant Hansenula polymorpha maltase produced in Escherichia coli hydrolyzed p-nitrophenyl-alpha-D-glucopyranoside (PNPG), sucrose, maltose and alpha-methylglucoside and did not act on melibiose, cellobiose, trehalose and o-nitrophenyl-beta-D-galactopyranoside (ONPG) [1].

High impact information on MAL12

• MALp reportedly is a regulatory gene required for inducible synthesis of the two enzymatic functions needed for fermentation: maltose permease and maltase [2].
• Upstream regulatory regions controlling the expression of the yeast maltase gene [3].
• This region contained an imperfect inverted repeat sequence (-361 to -327) or four copies of short direct repeats that might serve as components of the upstream activation site (UASM) for the maltase gene, or both [3].
• An ssn6 mutation was also shown to cause glucose-insensitive expression of a GAL10-lacZ fusion and maltase [4].
• Lentiginosine was found to be a reasonably good inhibitor of the fungal alpha-glucosidase, amyloglucosidase (Ki = 1 x 10(-5) M), but it did not inhibit other alpha-glucosidases (i.e., sucrase, maltase, yeast alpha-glucosidase, glucosidase I) nor any other glycosidases [5].

Biological context of MAL12

• The Hansenula polymorpha maltase structural gene (HPMAL1) was isolated from a genomic library by hybridization of the library clones with maltase-specific gene probe [1].
• A subcloned fragment of the coding sequence of the MAL6 maltase structural gene was used as a hybridization probe to investigate the physical structure of the family of MAL structural genes in the genomes of different Saccharomyces strains [6].
• Mutants with glucose repression-insensitive synthesis of alcohol oxidase and maltase were obtained from H. polymorpha by mutagenesis and subsequent selection on methanol medium in the presence of 2-deoxy-D-glucose [7].
• Gene dosage effects on the synthesis of maltase in yeast [8].
• DNA sequence analysis reveals that CAMAL2 encodes a 570-amino-acid protein which shares 50% identity with the maltase structural gene (MAL62) of Saccharomyces carlsbergensis [9].

Anatomical context of MAL12

• This study aimed at measuring invertase, maltase, lactase, and peroxidase activities in the duodenum of diabetesprone BioBreeding (BBdp) rats and control BioBreeding rats (BBc) given free access to NIH-07 diet up to the time of killing at 60 66 d of age [10].

Associations of MAL12 with chemical compounds

• Deletion of SWD3 resulted in larger amounts of MAL12 transcript, encoding maltase, at the late stages of fermentation of 22% maltose [11].
• These data show that expressing a suitable maltase on the cell surface might provide a means of modifying yeast for more complete maltotriose utilization in brewing and other fermentation applications [12].
• Its analysis revealed that H. polymorpha most probably has a repressor protein that in the presence of glucose can down-regulate expression of both maltase and enzymes of methanol oxidation [7].
• Maltase which hydrolyzes the alpha-1,4-disaccharide, maltose, and the alpha-1,6-disaccharide, isomaltose, catalyzes the formation of both maltose and isomaltose from free glucose [13].
• The affinity of maltase towards maltase substrates decreased in the order: 4-nitrophenyl glucoside (PNPG) < sucrose < maltose [7].

Other interactions of MAL12

• Mutations in the GGS1/TPS1 gene, which restricts glucose influx and possibly affects signalling, relieve carbon catabolite repression on both maltase and maltose permease and reduce maltose permease inactivation [14].
• The functional form of the PMU1 gene is required in addition to the MAL4 gene for both constitutive maltase synthesis and maltose utilization in cytoplasmic petite cells derived from strain 1403-7A-P1 [15].

Analytical, diagnostic and therapeutic context of MAL12

• The maltase structural gene sequences of each MaL locus were detected by Southern blot hybridization using BamH1 digests of genomic DNA of the meiotic products [6].
• Maltase was stable for 24 h at 60 degrees C over a pH range of 5.6 to 9.0 and retained 95% of the original activity after treatment for 20 min at 70 degrees C at pH 6.8 [16].

References