Identification of TER94, an AAA ATPase protein, as a Bam-dependent component of the Drosophila fusome.
The Drosophila fusome is a germ cell-specific organelle assembled from membrane skeletal proteins and membranous vesicles. Mutational studies that have examined inactivating alleles of fusome proteins indicate that the organelle plays central roles in germ cell differentiation. Although mutations in genes encoding skeletal fusome components prevent proper cyst formation, mutations in the bag-of-marbles gene disrupt the assembly of membranous cisternae within the fusome and block cystoblast differentiation altogether. To understand the relationship between fusome cisternae and cystoblast differentiation, we have begun to identify other proteins in this network of fusome tubules. In this article we present evidence that the fly homologue of the transitional endoplasmic reticulum ATPase (TER94) is one such protein. The presence of TER94 suggests that the fusome cisternae grow by vesicle fusion and are a germ cell modification of endoplasmic reticulum. We also show that fusome association of TER94 is Bam-dependent, suggesting that cystoblast differentiation may be linked to fusome reticulum biogenesis.
León
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Department of Molecular Biology and Oncology, University of Texas Southwestern Medical Center, Dallas, Texas 75235-9148, USA.
McKearin
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D000251:Adenosine Triphosphatases / Q000737:chemistry*; D000818:Animals; D018797:Cell Cycle Proteins / Q000378:metabolism*; D002999:Clone Cells; D004268:DNA-Binding Proteins / Q000378:metabolism; D004330:Drosophila / Q000201:enzymology*; D029721:Drosophila Proteins; D004721:Endoplasmic Reticulum / Q000378:metabolism; D029968:Escherichia coli Proteins; D005455:Fluorescent Antibody Technique; D006056:Golgi Apparatus / Q000378:metabolism; D019476:Insect Proteins / Q000378:metabolism*; D008561:Membrane Fusion; D009154:Mutation; D012333:RNA, Messenger / Q000378:metabolism; D012098:Reproduction; D015854:Up-Regulation; D000074405:Valosin Containing Protein
D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D029968:Escherichia coli Proteins; D019476:Insect Proteins; D012333:RNA, Messenger; C091674:bam protein, Drosophila; D000251:Adenosine Triphosphatases; C091277:TER ATPase; D000074405:Valosin Containing Protein