High impact information on fs(1)Ya

• The Drosophila maternal-effect gene fs(1)Ya encodes a cell cycle-dependent nuclear envelope component required for embryonic mitosis [1].
• In early embryos, the fs(1)Ya protein is localized to the nuclear envelope from interphase to metaphase [1].
• Interactions among Drosophila nuclear envelope proteins lamin, otefin, and YA [2].
• The ubiquitous major lamina protein, lamin Dm, interacts with both otefin, a peripheral protein of the inner nuclear membrane, and YA, an essential, developmentally regulated protein of the nuclear lamina [2].
• Our results suggest that interactions with lamin might mediate or stabilize the localization of otefin and YA in the nuclear lamina [2].

Biological context of fs(1)Ya

• Furthermore, cell cycle stage dependent nuclear localization is also seen for ectopically produced fs(1)Ya protein in tissue culture cells, neuroblasts, and male accessory glands, which are free of maternal products [3].
• Double mutant analyses between Ya and gnu suggest that YA plays a role in the nuclear envelope permissive for rounds of DNA replication [4].
• To define the function of YA in the nuclear envelope during early embryonic development, we characterized the phenotypes of four Ya mutants alleles and determined their molecular lesions [5].
• A model for YA function at the end of Drosophila female meiosis is proposed [6].
• Yeast two-hybrid analysis and transient transfection assays further defined this domain: residues 556-696 of YA are sufficient for both lamin Dm0 interaction and the targeting of GFP-NLS to the nuclear periphery [7].

Anatomical context of fs(1)Ya

• The Drosophila fs(1)Ya protein, which is needed for the first mitotic division, is in the nuclear lamina and in the envelopes of cleavage nuclei, pronuclei, and nonmitotic nuclei [3].
• Ectopically expressed YA is present in the nuclear envelopes of spermatocytes, but not in mature sperm, similar to endogenous lamin Dm [4].
• YA in ovaries is hyperphosphorylated relative to YA in unfertilized eggs and embryos [8].
• Drosophila P0/AP3, a ribosomal protein that is also an apurinic/apyrimidinic endonuclease, binds to YA in ovary and embryo cytoplasms [9].
• Mutant zygotes lacking functional YA arrest in the first division cycles following fertilization, hence having a 'Young Arrest' of their development [10].

Associations of fs(1)Ya with chemical compounds

• The Drosophila nuclear lamina protein YA binds to DNA and histone H2B with four domains [6].

Physical interactions of fs(1)Ya

• Here, we show that C-terminal lamin-interacting region of YA is sufficient to target the heterologous soluble protein GFP-NLS to the nuclear periphery in Drosophila tissue culture cells [7].

Enzymatic interactions of fs(1)Ya

• We propose that the P0-containing 20S cytoplasmic complex retains hyperphosphorylated ovarian YA in the cytoplasm [9].

Other interactions of fs(1)Ya

• Finally, our immunoelectron microscopy shows that the fs(1)Ya protein distribution parallels that of lamin, indicating that it is a nuclear lamina protein [3].
• P0 and YA bind specifically and directly in vitro and are present in a 20S complex in the cytoplasmic extracts [9].
• YA's binding to DNA and histone H2B is mediated by four domains distributed along the length of the YA molecule [6].

Analytical, diagnostic and therapeutic context of fs(1)Ya

• To investigate the cytoplasmic retention machinery that keeps YA from entering nuclei, we used affinity chromatography and blot overlay assays to identify cytoplasmic proteins that associate with YA [9].
• In support of this interaction, we demonstrated by immunoprecipitation that YA molecules are present in complexes with each other [11].
• Functional dissection of YA, an essential, developmentally regulated nuclear lamina protein in Drosophila melanogaster [11].

References