FUT10 and FUT11 are protein O-fucosyltransferases that modify protein EMI domains.

O-Fucosylation plays crucial roles in various essential biological events. Alongside the well-established O-fucosylation of epidermal growth factor-like repeats by protein O-fucosyltransferase 1 (POFUT1) and thrombospondin type 1 repeats by POFUT2, we recently identified a type of O-fucosylation on the elastin microfibril interface (EMI) domain of Multimerin-1 (MMRN1). Here, using AlphaFold2 screens, co-immunoprecipitation, enzymatic assays combined with mass spectrometric analysis and CRISPR-Cas9 knockouts, we demonstrate that FUT10 and FUT11, originally annotated in UniProt as α1,3-fucosyltransferases, are actually POFUTs responsible for modifying EMI domains; thus, we renamed them as POFUT3 and POFUT4, respectively.

Analysis of the Healthy Platelet Proteome Identifies a New Form of Domain-Specific O-Fucosylation.

Platelet activation induces the secretion of proteins that promote platelet aggregation and inflammation. However, detailed analysis of the released platelet proteome is hampered by platelets' tendency to preactivate during their isolation and a lack of sensitive protocols for low abundance releasate analysis. Here, we detail the most sensitive analysis to date of the platelet releasate proteome with the detection of >1300 proteins.

Differential Labeling of Glycoproteins with Alkynyl Fucose Analogs.

Fucosylated glycans critically regulate the physiological functions of proteins and cells. Alterations in levels of fucosylated glycans are associated with various diseases. For detection and functional modulation of fucosylated glycans, chemical biology approaches using fucose (Fuc) analogs are useful.

Inhibition of Delta-induced Notch signaling using fucose analogs.

Notch is a cell-surface receptor that controls cell-fate decisions and is regulated by O-glycans attached to epidermal growth factor-like (EGF) repeats in its extracellular domain. Protein O-fucosyltransferase 1 (Pofut1) modifies EGF repeats with O-fucose and is essential for Notch signaling. Constitutive activation of Notch signaling has been associated with a variety of human malignancies.

-Glycosylation modulates the stability of epidermal growth factor-like repeats and thereby regulates Notch trafficking.

Glycosylation in the endoplasmic reticulum (ER) is closely associated with protein folding and quality control. We recently described a non-canonical ER quality control mechanism for folding of thrombospondin type 1 repeats by protein -fucosyltransferase 2 (POFUT2). Epidermal growth factor-like (EGF) repeats are also small cysteine-rich protein motifs that can be -glycosylated by several ER-localized enzymes, including protein -glucosyltransferase 1 (POGLUT1) and POFUT1.

Design and synthesis of N-(5-chloro-2,4-dihydroxybenzoyl)-(R)-1,2,3,4-tetrahydroisoquinoline-3-carboxamides as novel Hsp90 inhibitors.

Heat shock protein 90 (Hsp90) is an attractive chemotherapeutic target for antitumor drug development. Herein, we reported the design and synthesis of two series of novel N-(5-chloro-2,4-dihydroxybenzoyl)-1,2,3,4-tetrahydroisoquinoline-3- carboxamides as Hsp90 inhibitors using (S)-Tic (1,2,3,4-tetrahydroisoquinoline-3- carboxylic acid) (A1-13) and (R)-Tic (B1-13) as scaffold, respectively. Cellular thermal shift assay (CETSA) screening showed that compounds B1-13 with (R)-Tic scaffold exhibited potent ability to stabilize Hsp90α.

Avertoxins A-D, Prenyl Asteltoxin Derivatives from Aspergillus versicolor Y10, an Endophytic Fungus of Huperzia serrata.

Aspergillus versicolor Y10 is an endophytic fungus isolated from Huperzia serrata, which showed inhibitory activity against acetylcholinesterase. An investigation of the chemical constituents of Y10 led to the isolation of four new prenylated asteltoxin derivatives, named avertoxins A-D (2-5), together with the known mycotoxin asteltoxin (1). In the present study, we report structure elucidation for 2-5 and the revised NMR assignments for asteltoxin and demonstrated that avertoxin B (3) is an active inhibitor against human acetylcholinesterase with the IC50 value of 14.

Design and synthesis of 2-phenylnaphthalenoids and 2-phenylbenzofuranoids as DNA topoisomerase inhibitors and antitumor agents.

Eight 2-phenylnaphthalenoids (2PNs) (3a-h) and twenty four 2-phenylbenzofuranoids (2PBFs) (4a--4j, 5a-5j, 6a, 6f-6h) were successfully designed, synthesized and their antiproliferative and in vitro DNA topoisomerase inhibitory activities were evaluated. Nine compounds (four 2PNs and five 2PBFs) showed either TopoI or TopoIIα inhibitory activities. Six compounds (four 2PNs and two 2PBFs) exhibited potent cytotoxicity with IC50 values for 72 h exposure ranging from 0.

Nocarbenzoxazoles A-G, Benzoxazoles Produced by Halophilic Nocardiopsis lucentensis DSM 44048.

Seven new benzoxazole derivatives, nocarbenzoxazoles A-G (1-7), were isolated from the halophilic strain Nocardiopsis lucentensis DSM 44048. Their structures were elucidated on the basis of 1D and 2D NMR spectroscopic data, HRESIMS, and X-ray single-crystal diffraction. The isolated compounds were assayed for their cytotoxicity against a panel of human tumor cell lines (HepG2, MDA-MB-231, MDA-MB-435, HeLa, and PC3).

Discovery of diamine-linked 17-aroylamido-17-demethoxygeldanamycins as potent Hsp90 inhibitors.

Heat shock protein 90 (Hsp90) is an attractive target for the development of antitumor agents. Geldanamycin (GA), the first Hsp90 inhibitor, has potent antitumor activity, but showed significant hepatotoxicity. To get rid of the hepatotoxicity of GA, in this study we incorporated aroyl groups via three types of linkers (4-aminomethylpiperidine, 1,4-butanediamine, and 1,6-hexanediamine) to the 17-position of GA and synthesized fifty-three 17-diamine-linked 17-aroylamido-17-demethoxygeldanamycins.

CS1 is a novel topoisomerase IIα inhibitor with favorable drug resistance profiles.

DNA topoisomerase II (Topo II) is an essential nuclear enzyme and a validated target for anticancer agent screening. CS1, a novel 2-phenylnaphthalene, had potent cytotoxicity against nine tested tumor cell lines and showed 6-10-fold less toxicity against normal cell lines compared with etoposide. In addition, CS1 showed potential anti-multidrug resistance capabilities.

Design, synthesis and biological evaluation of 17-arylmethylamine-17-demethoxygeldanamycin derivatives as potent Hsp90 inhibitors.

Thirty-three 17-arylmethylamine-substituted derivatives of geldanamycin (GA) were designed, synthesized and evaluated for the anti-proliferation activity on human cancer cell lines, LNCaP and MDA-MB-231. Three derivatives (22, 33 and 34) exhibited potent cytotoxicity with IC50 values range from 0.05 to 0.

p-Terphenyl O-β-glucuronides, DNA topoisomerase inhibitors from Streptomyces sp. LZ35ΔgdmAI.

The analysis of genome sequence indicated that Streptomyces sp. LZ35 has the potential of producing many types of secondary metabolites, including p-terphenyls and geldanamycins. The fermentation of LZ35 in laboratory produces geldanamycins as the major components, which hampers the isolation of minor compounds.