title: The C-terminus of human glutaminase L mediates association with PDZ domain-containing proteins.
abstract: The enzyme glutaminase in brain is responsible for the synthesis of neurotransmitter glutamate. We used the two-hybrid genetic selection system in yeast to look for interactors of glutaminase in human brain. We have identified two proteins containing PDZ domains, alpha1-syntrophin and a glutaminase-interacting protein, named GIP, that showed association with human glutaminase L, as deduced from specificity test of the two-hybrid system. The complete GIP cDNA clone has 1315 nucleotides with a 372-base open reading frame encoding a 124-amino acids protein. Glutaminase associates with both PDZ proteins through its C-terminal end; mutagenesis of single amino acids revealed the sequence -ESXV as essential for the interaction. These data suggest the possibility that PDZ domain-containing proteins are involved in the regulation of glutaminase in brain.
authors.affiliation: Departamento de Biología Molecular y Bioquímica, Laboratorio de Química de Proteínas, Facultad de Ciencias, Universidad de Málaga, 29071, Málaga, Spain.
authors.forename: L
authors.initials: L
authors.lastname: Olalla
authors.forename: J C
authors.initials: JC
authors.lastname: Aledo
authors.forename: G
authors.initials: G
authors.lastname: Bannenberg
authors.forename: J
authors.initials: J
authors.lastname: Márquez
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D001665:Binding Sites; D001921:Brain / Q000378:metabolism; D002135:Calcium-Binding Proteins; D005972:Glutaminase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D007527:Isoenzymes / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D008565:Membrane Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D009124:Muscle Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D009154:Mutation / Q000235:genetics; D018377:Neurotransmitter Agents; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D016415:Sequence Alignment; D020798:Two-Hybrid System Techniques
chemical_list: D002135:Calcium-Binding Proteins; D047908:Intracellular Signaling Peptides and Proteins; D007527:Isoenzymes; D008565:Membrane Proteins; D009124:Muscle Proteins; D018377:Neurotransmitter Agents; C421249:TAX1BP3 protein, human; C091825:syntrophin alpha1; D005972:Glutaminase