title: MALT1 is not alone after all: identification of novel paracaspases.
abstract: Paracaspases and metacaspases are two families of caspase-like proteins identified in 2000. Up until now paracaspases were considered a single gene family with one known non-metazoan paracaspase in the slime mold Dictyostelium and a single animal paracaspase called MALT1. Human MALT1 is a critical signaling component in many innate and adaptive immunity pathways that drive inflammation, and when it is overly active, it can also cause certain forms of cancer. Here, we report the identification and functional analysis of two new vertebrate paracaspases, PCASP2 and PCASP3. Functional characterization indicates that both scaffold and protease functions are conserved across the three vertebrate paralogs. This redundancy might explain the loss of two of the paralogs in mammals and one in Xenopus. Several of the vertebrate paracaspases currently have incorrect or ambiguous annotations. We propose to annotate them accordingly as PCASP1, PCASP2, and PCASP3 similar to the caspase gene nomenclature. A comprehensive search in other metazoans and in non-metazoan species identified additional new paracaspases. We also discovered the first animal metacaspase in the sponge Amphimedon. Comparative analysis of the active site suggests that paracaspases constitute one of the several subclasses of metacaspases that have evolved several times independently.
authors.affiliation: Inflammation Research Center, VIB, Ghent, Belgium.|Department of Biomedical Molecular Biology, Unit of Molecular Signal Transduction in Inflammation, Ghent University, Technologiepark 927, 9052, Ghent, Belgium.
authors.forename: Paco
authors.initials: P
authors.lastname: Hulpiau
authors.affiliation: Inflammation Research Center, VIB, Ghent, Belgium.|Department of Biomedical Molecular Biology, Unit of Molecular Signal Transduction in Inflammation, Ghent University, Technologiepark 927, 9052, Ghent, Belgium.
authors.forename: Yasmine
authors.initials: Y
authors.lastname: Driege
authors.affiliation: Inflammation Research Center, VIB, Ghent, Belgium. jens.staal@irc.vib-ugent.be.|Department of Biomedical Molecular Biology, Unit of Molecular Signal Transduction in Inflammation, Ghent University, Technologiepark 927, 9052, Ghent, Belgium. jens.staal@irc.vib-ugent.be.
authors.forename: Jens
authors.initials: J
authors.lastname: Staal
authors.affiliation: Inflammation Research Center, VIB, Ghent, Belgium. Rudi.Beyaert@irc.vib-UGent.be.|Department of Biomedical Molecular Biology, Unit of Molecular Signal Transduction in Inflammation, Ghent University, Technologiepark 927, 9052, Ghent, Belgium. Rudi.Beyaert@irc.vib-UGent.be.
authors.forename: Rudi
authors.initials: R
authors.lastname: Beyaert
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D020169:Caspases / Q000737:chemistry / Q000235:genetics*; D020134:Catalytic Domain; D002645:Chickens; D063990:Gene Ontology; D006801:Humans; D008969:Molecular Sequence Data; D000074884:Mucosa-Associated Lymphoid Tissue Lymphoma Translocation 1 Protein; D009363:Neoplasm Proteins / Q000737:chemistry / Q000235:genetics*; D010802:Phylogeny; D011161:Porifera; D016415:Sequence Alignment; D015027:Zebrafish
chemical_list: D009363:Neoplasm Proteins; D020169:Caspases; C400109:MALT1 protein, human; D000074884:Mucosa-Associated Lymphoid Tissue Lymphoma Translocation 1 Protein
keywords: CYLD; Chicken; Evolution; MALT1; NF-κB; Protease; Xenopus; Zebrafish