High impact information on ALR1

• The Saccharomyces cerevisiae ALR1 (YOL130w) gene product Alr1p is the first known candidate for a Mg(2+) transport system in eukaryotic cells and is distantly related to the bacterial CorA Mg(2+) transporter family [1].
• Furthermore, cells lacking the vacuolar protease Pep4p accumulated Alr1p in the vacuole [1].
• Mutants lacking Alr1p (Deltaalr1) showed a 60% reduction of total intracellular Mg(2+) compared with the wild type and failed to grow in standard media [1].
• The yeast plasma membrane protein Alr1 controls Mg2+ homeostasis and is subject to Mg2+-dependent control of its synthesis and degradation [1].
• Yeast strains lacking ALR gene activity required additional Mg2+ for growth, and expression of either ALR1 or ALR2 corrected the Mg(2+)-requiring phenotype [2].

Biological context of ALR1

• Disruption of YOL130w (also known as ALR1) produced a lethal phenotype, despite the presence of a highly similar gene in the yeast genome (ALR2/YFL050C) [3].
• Random PCR mutagenesis was undertaken of the C-terminal part of ALR1 that is homologous to the bacterial CorA magnesium transport family [4].

Anatomical context of ALR1

• When Mg(2+) was the major cation in the pipette solution, time-dependent outward currents were also detected in CM66+ALR1 protoplasts suggesting ALR1 can facilitate Mg(2+) efflux as well as uptake [5].

Associations of ALR1 with chemical compounds

• The function of Alr1p of Saccharomyces cerevisiae in cadmium detoxification: insights from phylogenetic studies and particle-induced X-ray emission [6].
• ALR1 is strictly specific for NADPH (2.4 x 10(5) M(-1) s(-1)) whereas ALR2 utilises NADH and NADPH with similar specificity constants of approximately 2-4 x 10(5) M(-1) s(-1) [7].

Other interactions of ALR1

• Two genes in Saccharomyces cerevisiae, ALR1 and ALR2, encode transmembrane proteins involved in Mg2+ uptake [6].
• Alr1-type proteins are distant relatives of the mitochondrial and bacterial Mg(2+)-transport proteins, Mrs2p and CorA, respectively, with which they have two adjacent TM domains and a short Mg(2+) signature motif in common [8].

Analytical, diagnostic and therapeutic context of ALR1

• The patch-clamp technique was used to measure whole-cell ion currents in protoplasts prepared from the wild-type strain, the alr1 alr2 double mutant (CM66), and the double mutant over-expressing the ALR1 gene (CM66+ALR1) [5].

References