Centrosomes are major determinants of mitotic spindle structure, but the mechanisms regulating their behavior remain poorly understood. The spd-2 gene of C. elegans is required for centrosome assembly or "maturation." Here we show that spd-2 encodes a coiled-coil protein that localizes within pericentriolar material (PCM) and in the immediate vicinity of centrioles. During maturation, SPD-2 gradually accumulates at the centrosome in a manner that is partially dependent on Aurora-A kinase and cytoplasmic dynein. Interestingly, SPD-2 interacts genetically with dynein heavy chain and SPD-5, another coiled-coil protein required for centrosome maturation. SPD-2 and SPD-5 are codependent for localization to the PCM, but SPD-2 localizes to centrioles independently of SPD-5. Surprisingly, we also find that SPD-2 is required for centrosome duplication and genetically interacts with ZYG-1, a kinase required for duplication. Thus, we have identified SPD-2 as a factor critical for the two basic functions of the centrosome-microtubule organization and duplication.
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http://dx.doi.org/10.1016/s1534-5807(04)00066-8 | DOI Listing |
Organisms with smaller genomes often perform multiple functions using one multi-subunit protein complex. The Silent Information Regulator complex (SIRc) carries out all of the core functions of heterochromatin. SIR complexes first drive the initiation and spreading of histone deacetylation in an iterative manner.
View Article and Find Full Text PDFPLoS One
January 2025
Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai, India.
Nucleocytoplasmic large DNA viruses (NCLDVs) have massive genome and particle sizes compared to other known viruses. NCLDVs, including poxviruses, encode ATPases of the FtsK/HerA superfamily to facilitate genome encapsidation. However, their biochemical and structural characteristics are yet to be discerned.
View Article and Find Full Text PDFNat Commun
January 2025
Zentrum für Molekulare Biologie der Universität Heidelberg (ZMBH), Heidelberg, Germany.
The γ-tubulin ring complex (γ-TuRC) is a structural template for controlled nucleation of microtubules from α/β-tubulin heterodimers. At the cytoplasmic side of the yeast spindle pole body, the CM1-containing receptor protein Spc72 promotes γ-TuRC assembly from seven γ-tubulin small complexes (γ-TuSCs) and recruits the microtubule polymerase Stu2, yet their molecular interplay remains unclear. Here, we determine the cryo-EM structure of the Candida albicans cytoplasmic nucleation unit at 3.
View Article and Find Full Text PDFJ Control Release
January 2025
State Key Laboratory of Component-based Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin 301617, China; Institute of Traditional Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin 301617, China; Haihe Laboratory of Modern Chinese Medicine, Tianjin 301617, China. Electronic address:
Drug resistance to chemotherapy in treating cancers becomes an increasingly serious challenge, which leads to treatment failure and poor patient survival. Drug-resistant cancer cells normally reduce intracellular accumulation of drugs by controlling drug uptake and promoting drug efflux, which severely limits the efficacy of chemotherapy. To overcome this problem, a membrane fused drug delivery system (MF-DDS) was constructed to treat cisplatin (DDP)-resistant lung cancer (A549-DDP) by delivering DDP via membrane fusion using a complementary coiled-coil forming peptides (CPK/CPE).
View Article and Find Full Text PDFNat Commun
January 2025
State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China.
WNT/β-catenin signaling plays key roles in development and cancer. ZNRF3/RNF43 modulates Frizzleds through ubiquitination, dampening WNT/β-catenin signaling. Conversely, RSPO1-4 binding to LGR4-6 and ZNRF3/RNF43 enhances WNT/β-catenin signaling.
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