title: On the roles of the Drosophila KASH domain proteins Msp-300 and Klarsicht.
abstract: KASH (Klarsicht, Anc-1, Syne-1 homology) domain-containing proteins anchor the nucleus to the actin cytoskeleton or to microtubules. KASH proteins thus play pivotal roles in a variety of developmental processes where nuclear positioning is critical. Two KASH proteins have been identified in Drosophila: Muscle-specific protein-300 (Msp-300) and Klarsicht (Klar). Msp-300 anchors nuclei to actin, and has been reported to be essential for positioning of nurse cell nuclei during oogenesis, and thus production of mature ooctyes. Klar is required for positioning of photoreceptor and cone cell nuclei in the developing eye, which is critical for proper eye morphology. Here, we asked whether KASH domain-containing forms of Msp-300 are required for nuclear positioning in the eye, and we found that they are not. Moreover, in the course of this work, we discovered that contrary to previous reports, KASH domain-containing forms of Msp-300 are not required for viability, nor for oogenesis. However, we did find that Msp-300 has a function in egg laying, normally redundant with a function of Klar.
authors.affiliation: Section of Molecular Cell and Developmental Biology, Institute for Cell and Molecular Biology, The University of Texas at Austin, Austin, Texas 78712, USA.
authors.forename: Xuanhua
authors.initials: X
authors.lastname: Xie
authors.forename: Janice A
authors.initials: JA
authors.lastname: Fischer
mesh_terms: D000818:Animals; D054910:Compound Eye, Arthropod / Q000196:embryology* / Q000378:metabolism; D004330:Drosophila / Q000196:embryology* / Q000235:genetics / Q000378:metabolism; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D005091:Exons; D005260:Female; D005298:Fertility; D006720:Homozygote; D007814:Larva / Q000378:metabolism; D008297:Male; D026901:Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism*; D008840:Microfilament Proteins / Q000235:genetics / Q000378:metabolism*; D022101:Microtubule-Organizing Center / Q000378:metabolism; D009124:Muscle Proteins / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D009865:Oocytes / Q000378:metabolism; D010053:Ovary / Q000196:embryology; D017434:Protein Structure, Tertiary; D011679:Pupa / Q000378:metabolism
chemical_list: D029721:Drosophila Proteins; D026901:Membrane Transport Proteins; D008840:Microfilament Proteins; C079806:Msp300 protein, Drosophila; D009124:Muscle Proteins; C401521:klar protein, Drosophila