The Drosophila centrosomal protein Nuf is required for recruiting Dah, a membrane associated protein, to furrows in the early embryo.
During mitosis of the Drosophila cortical syncytial divisions, actin-based membrane furrows separate adjacent spindles. Our genetic analysis indicates that the centrosomal protein Nuf is specifically required for recruitment of components to the furrows and the membrane-associated protein Dah is primarily required for the inward invagination of the furrow membrane. Recruitment of actin, anillin and peanut to the furrows occurs normally in dah-derived embryos. However, subsequent invagination of the furrows fails in dah-derived embryos and the septins become dispersed throughout the cytoplasm. This indicates that stable septin localization requires Dah-mediated furrow invagination. Close examination of actin and Dah localization in wild-type embryos reveals that they associate in adjacent particles during interphase and co-localize in the invaginating furrows during prophase and metaphase. We show that the Nuf centrosomal protein is required for recruiting the membrane-associated protein Dah to the furrows. In nuf-mutant embryos, much of the Dah does not reach the furrows and remains in a punctate distribution. This suggests that Dah is recruited to the furrows in vesicles and that the recruiting step is disrupted in nuf mutants. These studies lead to a model in which the centrosomes play an important role in the transport of membrane-associated proteins and other components to the developing furrows.
Rothwell
W F
WF
Sinsheimer Laboratories, Department of Biology, University of California, Santa Cruz, CA 95064, USA.
Zhang
C X
CX
Zelano
C
C
Hsieh
T S
TS
Sullivan
W
W
D000199:Actins / Q000378:metabolism; D000818:Animals; D018385:Centrosome / Q000378:metabolism*; D003285:Contractile Proteins / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000196:embryology* / Q000235:genetics; D004625:Embryo, Nonmammalian / Q000648:ultrastructure; D019476:Insect Proteins / Q000235:genetics / Q000378:metabolism* / Q000502:physiology*; D007399:Interphase; D008565:Membrane Proteins; D008677:Metaphase; D008840:Microfilament Proteins; D020409:Molecular Motor Proteins; D009024:Morphogenesis; D009687:Nuclear Proteins / Q000235:genetics / Q000502:physiology*; D011418:Prophase
D000199:Actins; D003285:Contractile Proteins; C101042:Dah protein, Drosophila; D029721:Drosophila Proteins; D019476:Insect Proteins; D008565:Membrane Proteins; D008840:Microfilament Proteins; D020409:Molecular Motor Proteins; D009687:Nuclear Proteins; C095886:anillin; C111662:nuf protein, Drosophila; C087195:pnut protein, Drosophila