High impact information on scf

• Two papers by Guardavaccaro et al. and Margottin-Goguet et al. in the June issue of Developmental Cell now show that Emi1 degradation in early mitosis is mediated by beta-Trcp1, an adaptor protein that recruits proteins to the SCF ubiquitin ligase [1].
• DNA supercoiling factor (SCF) was first identified in silkworm as a protein that generates negative supercoils in DNA in conjunction with eukaryotic topoisomerase II [2].
• DNA supercoiling factor localizes to puffs on polytene chromosomes in Drosophila melanogaster [2].
• These results implicate SCF in gene expression [2].
• Immunostaining of blastoderm embryos showed that SCF is present in nuclei during interphase but is excluded from mitotic chromosomes [2].

Biological context of scf

• Functional dissection of DNA supercoiling factor: EF-hand domains and C-terminal HDEF motif are essential for its activity [3].
• Upon overexpression of SCF, the male X chromosome had a bloated appearance [4].
• Upon knockdown of SCF, we observed male lethality and male-specific reduction in the expression levels of X-linked genes [4].
• These findings demonstrate that SCF plays a role in transcriptional activation via alteration of chromatin structure and provide evidence that SCF contributes to dosage compensation [4].
• SKPa is component of a Drosophila SCF complex that functions in combination with the ubiquitin-conjugating enzyme UbcD1. skpA null mutation results in centrosome overduplication, unusual chromatin condensation, defective endoreduplication and cell-cycle progression [5].

Anatomical context of scf

• We also show that Archipelago (Ago), a SCF-regulator is dispensable for mitosis, but crucial for endocycle progression in follicle epithelium [6].
• These data suggest that additional SCF targets regulate the centrosome duplication pathway [7].

Associations of scf with chemical compounds

• During native polyacrylamide gel electrophoresis, SCF migrated more rapidly in the presence of Ca2+ than in the presence of Mg2+ or EGTA [3].

Physical interactions of scf

• SCF binds directly to topoisomerase II [3].

Analytical, diagnostic and therapeutic context of scf

• RESULTS: To clarify the roles of the domains of SCF, we carried out a functional dissection of the factor [3].

References