Latrunculin B

Latrunculin B is a cell-permeable actin polymerization inhibitor in vitro and in vivo by the formation of a 1:1 complex with monomeric G-actin and thereby inhibit actin polymerization.Latrunculin B regulates pulmonary vein electrophysiological characteristics and attenuates stretch-induced arrhythmogenesis ^[1].

Latrunculin B (0-10μM; 60min) treatment of CH27 cells depolymerized actin filaments. Treatment of cells with Latrunculin B (0.1μM; 30min) reduced ghost pen cyclic peptide staining and resulted in changes in the cellular distribution of BCR ^[2].Latrunculin B (100nM; 30min) decreases the late Na⁺ current, L-type Ca²⁺ current, Na⁺/Ca²⁺ exchanger current, and stretch-activated BKCa current in PV cardiomyocytes ^[3]. Latrunculin B displays growth inhibition of HeLa cells with an IC₅₀ value of 1.4μM ^[4].

Latrunculin B (0.5μM/day; ip; 2months) restored the frequency and number of FO B cells in Rictor KO mice compared with Rictor KO mice treated with vector only, but had no effect on MZ B cell formation, and also restored the levels of pY or pBtk in Rictor KO mice ^[5]. Treatment of eggs with latrunculin B (5, 10 and 20μg/ml; 90min) resulted in a decrease in the incidence of fertilization ^[6].

References:
[1] Youssef D T A, Asfour H Z, Genta-Jouve G, et al. Magnificines A and B, antimicrobial marine alkaloids featuring a tetrahydrooxazolo [3, 2-a] azepine-2, 5 (3H, 6H)-dione backbone from the Red Sea sponge Negombata magnifica[J]. Marine Drugs, 2021, 19(4): 214.
[2] Brown BK, Song W. The actin cytoskeleton is required for the trafficking of the B cell antigen receptor to the late endosomes. Traffic. 2001 Jun;2(6):414-27.
[3]Lu Y Y, Lin Y K, Wen Z H, et al. Latrunculin B modulates electrophysiological characteristics and arrhythmogenesis in pulmonary vein cardiomyocytes[J]. Clinical Science, 2016, 130(9): 721-732.
[4] oussef DTA, Asfour HZ, Genta-Jouve G, Shaala LA. Magnificines A and B, Antimicrobial Marine Alkaloids Featuring a Tetrahydrooxazolo[3,2-a]azepine-2,5(3H,6H)-dione Backbone from the Red Sea Sponge Negombata magnifica. Mar Drugs. 2021 Apr 12;19(4):214.
[5] Huang L, Zhang Y, Xu C, Gu X, Niu L, Wang J, Sun X, Bai X, Xuan X, Li Q, Shi C, Yu B, Miller H, Yang G, Westerberg LS, Liu W, Song W, Zhao X, Liu C. Rictor positively regulates B cell receptor signaling by modulating actin reorganization via ezrin. PLoS Biol. 2017 Aug 18;15(8):e2001750.
[6] McAvey BA, Wortzman GB, Williams CJ, Evans JP. Involvement of calcium signaling and the actin cytoskeleton in the membrane block to polyspermy in mouse eggs. Biol Reprod. 2002 Oct;67(4):1342-52.

Latrunculin B 是一种可穿透细胞的肌动蛋白聚合抑制剂，在体外和体内可通过与单体 G-actin形成 1:1 复合物来抑制肌动蛋白聚合。Latrunculin B 调节肺静脉电生理特性并减弱拉伸诱导的心律失常发生^[1]。

Latrunculin B（0-10μM；60min）处理 CH27 细胞可使肌动蛋白丝解聚。用 Latrunculin B（0.1μM；30min） 处理细胞可减少鬼笔环肽染色，并导致 BCR 的细胞分布发生变化^[2]。Latrunculin B （100 nM；30min） 降低 PV 心肌细胞中的晚期 Na ⁺ 电流、L 型 Ca²⁺ 电流、Na ⁺ / Ca^{2 +} 交换电流和拉伸激活的 BKCa 电流^[3]。Latrunculin B 可抑制 HeLa 细胞的生长，其 IC₅₀ 值为 1.4μM^[4]。

与只用载体处理的 Rictor KO 小鼠相比，Latrunculin B（0.5μM/day ; ip；2months）能恢复 Rictor KO 小鼠 FO B 细胞的频率和数量，但对 MZB 细胞的形成没有影响，还能恢复 Rictor KO 小鼠 pY 或 pBtk 的水平^[5]。用 Latrunculin B（5、10 、20 μg/ml；90 min）处理卵子会导致受精率下降 ^[6]。