The product of the SHR3 orthologue of Aspergillus nidulans has restricted range of amino acid transporter targets.
The shrA gene of Aspergillus nidulans codes for a structural and functional homologue of Shr3p, a yeast ER membrane protein, which plays a crucial role in the secretory pathway of yeast amino acid permeases. shrA is a single-copy gene, whose expression is early activated during germination of A. nidulans conidiospores. ShrA is localized in the ER of the fungal cells and partially complements the shr3delta phenotype. Differently from Saccharomyces cerevisiae, where SHr3p is necessary for membrane localization of the majority of amino acid permeases, deletion of the shrA locus in A. nidulans impairs a limited number of amino acid uptake activities, including those responsible for proline and aspartate transport. Strongly reduced membrane levels of a PrnB-sGFP fusion in a shrAdelta background clearly suggest a direct role of ShrA in the topogenesis of the proline specific transporter.
Institute of Biology, National Center for Scientific Research, Demokritos (NCSR D), Aghia Paraskevi, 153 10 Athens, Greece.
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Erpapazoglou
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Kafasla
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Sophianopoulou
D000595:Amino Acid Sequence; D026905:Amino Acid Transport Systems / Q000378:metabolism*; D026921:Amino Acid Transport Systems, Neutral / Q000235:genetics; D019677:Artificial Gene Fusion; D001224:Aspartic Acid / Q000378:metabolism; D001233:Aspergillus nidulans / Q000378:metabolism*; D004721:Endoplasmic Reticulum / Q000737:chemistry; D005656:Fungal Proteins / Q000032:analysis / Q000502:physiology*; D017353:Gene Deletion; D015966:Gene Expression Regulation, Fungal; D017930:Genes, Reporter; D005816:Genetic Complementation Test; D049452:Green Fluorescent Proteins / Q000032:analysis / Q000235:genetics; D026901:Membrane Transport Proteins / Q000032:analysis / Q000502:physiology*; D008969:Molecular Sequence Data; D010802:Phylogeny; D011392:Proline / Q000378:metabolism; D012331:RNA, Fungal / Q000032:analysis; D012333:RNA, Messenger / Q000032:analysis; D012441:Saccharomyces cerevisiae / Q000235:genetics; D017386:Sequence Homology, Amino Acid
D026905:Amino Acid Transport Systems; D026921:Amino Acid Transport Systems, Neutral; D005656:Fungal Proteins; D026901:Membrane Transport Proteins; D012331:RNA, Fungal; D012333:RNA, Messenger; D049452:Green Fluorescent Proteins; D001224:Aspartic Acid; C033082:proline transporter; D011392:Proline