DNA double-strand break repair machinery in Penaeid crustaceans: A focus on the Non-Homologous End-Joining pathway.

DNA double-strand breaks (DSBs) are repaired through three major pathways: Non-Homologous End-Joining (NHEJ), Microhomology-Mediated End-Joining (MMEJ), and Homology-Directed Repair (HDR), each requiring a specific set of diverse proteins. Such pathways and their proteins have been studied in model organisms, including arthropods; however, DSB repair pathways are scarcely described in Crustacea, a taxon that includes the commercially valuable penaeid shrimps (Crustacea: Decapoda: Penaeidae). In this work, transcriptome and proteome databases of Penaeus vannamei and other Crustacea species were scrutinized for each protein of the NHEJ pathway.

Proteolytic profile of larval developmental stages of Penaeus vannamei: An activity and mRNA expression approach.

In arthropods, the cleavage of specific proteins by peptidases has pivotal roles in multiple physiological processes including oogenesis, immunity, nutrition, and parasitic infection. These enzymes are also key players in the larval development, and well-described triggers of molting and metamorphosis. In this work the peptidase complement throughout the larvae development of Penaeus vannamei was quantified at the transcript and activity level using qPCR and fluorogenic substrates designed to be hydrolyzed by class-specific peptidases respectively, providing a detailed identification of the proteolytic repertoire in P.

Is digestive cathepsin D the rule in decapod crustaceans?

Cathepsin D is an aspartic endopetidase with typical characteristics of lysosomal enzymes. Cathepsin D activity has been reported in the gastric fluid of clawed lobsters where it acts as an extracellular digestive enzyme. Here we investigate whether cathepsin D is unique in clawed lobsters or, instead, common in decapod crustaceans.

American lobster Cathepsin D, an aspartic peptidase resistant to proteolysis and active in organic solvents, non-ionic detergents and salts.

Suitable peptidases for biotechnological applications are those active at low temperature, in organic solvents, detergents or proteolytic additives. American lobster cathepsin D1 (CD1) is an enzyme highly efficient at 5-50°C and at pH 2.5-5.

Proteinases during Early Development of the Pacific Whiteleg Shrimp Penaeus vannamei.

During shrimp larval development, changes occur in molecular components. Enzyme activity and mRNA expression of proteinases were assayed in Penaeus vannamei during larval development, which consists of 5 nauplius stages, 3 protozoeal stages, 3 mysis stages, and 12 postlarval stages. Trypsin activity reached a maximum at the beginning of postlarval stages 1 and 2, and significantly decreased in subsequent postlarval stages.