Identification and Functional Analysis of Apoptotic Protease Activating Factor-1 (Apaf-1) from Spodoptera litura

Abstract

Apoptotic protease activating factor-1 (Apaf-1) is an adaptor molecule, essential for activating initiator caspase and downstream effector caspases, which directly cause apoptosis. In fruit flies, nematodes, and mammals, Apaf-1 has been extensively studied. However, the structure and function of Apaf-1 in Lepidoptera remain unclear. This study identified a novel Apaf-1 from Spodoptera litura, named Sl-Apaf-1. Sl-Apaf-1 contains three domains: a CARD domain, as well as NOD and WD motifs, and is very similar to mammalian Apaf-1. Interference of Sl-apaf-1 expression in SL-1 cells blocked apoptosis induced by actinomycin D. Overexpression of Sl-apaf-1 significantly enhances apoptosis induced by actinomycin D in Sf9/SL-1/U2OS cells, suggesting that the function of Sl-Apaf-1 is evolutionarily conserved. Furthermore, Sl-Apaf-1 could interact with Sl-caspase-5 (a homologue of mammalian caspase-9) and yielded a binding affinity of 1.37 × 106 M–1 according isothermal titration calorimetry assay. Initiator caspase (procaspase-5) of S. litura could be activated by Sl-Apaf-1 (without WD motif) in vitro, and the activated Sl-caspase-5 could cleave Sl-procaspase-1 (a homologue of caspase-3 in mammals), which directly caused apoptosis. This study demonstrates the key role of Sl-Apaf-1 in the apoptosis pathway, suggesting that the apoptosis pathway in Lepidopteran insects and mammals is conserved.

Infection of Galleria mellonella (Lepidoptera) Larvae With the Entomopathogenic Fungus Conidiobolus coronatus (Entomophthorales) Induces Apoptosis of Hemocytes and Affects the Concentration of Eicosanoids in the Hemolymph

“…In contrast, very little is known about apoptotic molecular pathways in the Lepidoptera ( Ma et al, 2021 ). The discovery in the early 1990s of p35, a baculovirus pan-caspase inhibitor ( Clem et al, 1991 ), led to the characterization of the first lepidopteran caspase, Sf-caspase-1, from a Sf9 cell line, derived from Spodoptera frugiperda ovary cells ( Ahmad et al, 1997 ).…”

“…Other analogs to this caspase have been identified in Spodoptera littoralis (Sl-caspase-1), Spodoptera litura (Sl-Apaf-1), Helicoverpa armiger (Hearm caspase-1), and Trichloplusia ni ( Accorsi et al, 2015 ; Ma et al, 2021 ). In the silkworm Bombyx mori , two initiator caspase genes (Nedd2-like 1 and Nedd2-like 2) and Bm-caspase-1have been described ( Tian et al, 2012 ; Wang et al, 2017 ).…”

A Multifunctional Photoacoustic/Fluorescence Dual‐Mode‐Imaging Gold‐Based Theranostic Nanoformulation without External Laser Limitations

“…[ 36 ] Apoptotic protease activating factor‐1 (Apaf‐1) is an adaptor molecule that is crucial for activating initiator caspases and downstream effector caspases, which causes apoptosis directly. [ 37 ] Cyclin D1 has been recognized as a proto‐oncogene and its overexpression can cause uncontrolled cell proliferation and malignancy. Cyclin D1 gene overexpression and gene amplification have been observed in a variety of tumors.…”

Identification of polymorphism in APAF1 gene in holstein cattle

“…Поголовье животных, имеющих генотип QX в Японии и США, насчитывало 2,15 и 2,90 % соответственно [4,10]. Незначительное количество -0,88 и 0,24 % QX-типированных особей наблюдалось в популяциях колумбийского и индийского скота голштинской породы [7,13].…”

“…Активированная форма каспазы-9 инициирует каспаз-ный каскад, который в конечном итоге приводит к апоптотической гибели клеток [4, 17] APAF1 образует олигомер, который при контакте с цитохромом-с и dATP образует цитоплазматическую структуру апоптосомы, которая связывает препротеин каспазы-9 и расщепляет его до зрелой активной формы. Эти трансформации оказывают влияние на этиологию рака, нарушения развития и нейродегенеративные заболевания [13,15]…”