centrosomin's beautiful sister (cbs) encodes a GRIP-domain protein that marks Golgi inheritance and functions in the centrosome cycle in Drosophila.
The mechanism of inheritance of the Golgi complex is an important problem in cell biology. In this study, we examine the localization and function of a Golgi protein encoded by centrosomin's beautiful sister (cbs) during cleavage in Drosophila melanogaster. Cbs contains a GRIP domain that is 57% identical to vertebrate Golgin-97. Cbs undergoes a dramatic relocalization during mitosis from the cytoplasm to an association with chromosomes from late prometaphase to early telophase, by a transport mechanism that requires the GRIP domain and Arl1, the product of the Arf72A locus. Additionally, Cbs remains independent of the endoplasmic reticulum throughout cleavage. The use of RNAi, Arf72A mutant analysis and ectopic expression of the GRIP domain, shows that cycling of Cbs during mitosis is required for the centrosome cycle. The effects on the centrosome cycle depend on Cbs concentration and Cbs transport from the cytoplasm to DNA. When Cbs levels are reduced centrosomes fail to mature, and when Cbs transport is impeded by ectopic expression of the GRIP domain, centrosomes undergo hypertrophy. We propose that, Cbs is a trans-Golgi protein that links Golgi inheritance to the cell cycle and the Drosophila Golgi is more vertebrate-like than previously recognized.
Eisman
Robert C
RC
Department of Biology, Indiana University, Bloomington, IN 47405, USA.
Stewart
Natasha
N
Miller
David
D
Kaufman
Thomas C
TC
D020727:ADP-Ribosylation Factors / Q000235:genetics / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D001324:Autoantigens / Q000737:chemistry; D002352:Carrier Proteins / Q000378:metabolism*; D018385:Centrosome / Q000378:metabolism*; D003001:Cloning, Molecular; D003593:Cytoplasm / Q000378:metabolism; D004261:DNA Replication; D029721:Drosophila Proteins / Q000378:metabolism*; D004331:Drosophila melanogaster; D004721:Endoplasmic Reticulum / Q000378:metabolism; D005260:Female; D019204:GTP-Binding Proteins / Q000378:metabolism*; D006056:Golgi Apparatus / Q000378:metabolism*; D000077614:Golgi Matrix Proteins; D006168:Guinea Pigs; D018398:Homeodomain Proteins / Q000378:metabolism*; D007074:Immunoglobulin G / Q000276:immunology; D008565:Membrane Proteins; D008938:Mitosis; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D021381:Protein Transport; D034741:RNA, Small Interfering / Q000494:pharmacology; D017386:Sequence Homology, Amino Acid; D021601:trans-Golgi Network / Q000378:metabolism*
D001324:Autoantigens; D002352:Carrier Proteins; D029721:Drosophila Proteins; D000077614:Golgi Matrix Proteins; C450721:Golgi complex autoantigen, 97-kDa; C491307:Grip protein, Drosophila; D018398:Homeodomain Proteins; D007074:Immunoglobulin G; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D034741:RNA, Small Interfering; C098130:cnn protein, Drosophila; C097313:ADP-ribosylation factor related proteins; D019204:GTP-Binding Proteins; D020727:ADP-Ribosylation Factors