ISSN:
1617-4623
Keywords:
Key words Clathrin
;
Sorting
;
Tyrosine-based signal
;
Pigment
;
Hermansky-Pudlak syndrome
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract The adaptor protein (AP) complexes AP-1, AP-2, and AP-3 mediate coated vesicle formation and sorting of integral membrane proteins in the endocytic and late exocytic pathways in mammalian cells. A search of the Drosophila melanogaster expressed sequence tag (EST) database identified orthologs of family members mammalian medium (μ) chain families μ1, μ2, and μ3, of the corresponding AP complexes, and δ-COP, the analogous component of the coatomer (COPI) complex. The Drosophila orthologs exhibit a high degree of sequence identity to mammalian medium chain and δ-COP proteins. Northern analysis demonstrated that medium chain and δ-COP mRNAs are expressed uniformly throughout fly development. Medium chain and δ-COP genes were cytologically mapped and the μ3 gene was found to localize to a region containing the pigmentation locus carmine (cm). Analysis of genomic DNA of the cm 1 mutant allele indicated the presence of a large insertion in the coding region of the μ3 gene and Northern analysis revealed no detectable μ3 mRNA. Light microscopy of the cm 1 mutant showed a reduction in primary, secondary, and tertiary pigment granules in the adult eye. These findings provide evidence of a role for μ3 in the sorting processes required for pigment granule biogenesis in Drosophila.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s004380051099
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