Gracilariopsis chorda (Gracilariales, Florideophyceae) genome reveals highly duplication of CaMK genes in red algae

Abstract

The calcium/calmodulin-dependent Protein Kinases (CaMKs) are highly conserved proteins in all eukaryotes, and critically important for cellular function such as, gene transcription, protein translation, cell survival/death (apoptosis), and cytoskeletal reorganization. CaMK is one of the best characterized enzyme families of signaling pathways of Ca2+, calmodulin (CaM), CaM-kinase and CaM-binding targets in mammals. However, there was no information available on red algal CaMKs. Recently, we determined a draft genome of agar producing red algal species, Gracilariopsis chorda (Gracilariales, Florideophyceae), total 99.2 Mbp with 10,023 predicted genes. We compared all available red algal genomes (Chondrus crispus, Cyanidioschizon merolae 10D, Galdieria sulphuraria 074W, Porphyridium purpureum CCMP 1328, and Pyropia yezoensis U-51) and representative eukaryotic genomes. We uncovered red algal specific gene expansion of CaMK genes in red algae based on gene duplication analysis. The RNAseq data confirmed the successful expressions of all CaMKs of G. chorda under different conditions. Red algal CaMK genes clustered into seven clades based on the maximum likelihood analysis of total 808 red algal copies (including 134 from G. chorda) and other eukaryotes. This results support that CaMK duplication may relate to the acquisition of complex signaling among cells along the red algal evolution.cytoskeletal reorganization. CaMK is one of the best characterized enzyme families of signaling pathways of Ca2+, calmodulin (CaM), CaM-kinase and CaM-binding targets in mammals. However, there was no information available on red algal CaMKs. Recently, we determined a draft genome of agar producing red algal species, Gracilariopsis chorda (Gracilariales, Florideophyceae), total 99.2 Mbp with 10,023 predicted genes. We compared all available red algal genomes (Chondrus crispus, Cyanidioschizon merolae 10D, Galdieria sulphuraria 074W, Porphyridium purpureum CCMP 1328, and Pyropia yezoensis U-51) and representative eukaryotic genomes. We uncovered red algal specific gene expansion of CaMK genes in red algae based on gene duplication analysis. The RNAseq data confirmed the successful expressions of all CaMKs of G. chorda under different conditions. Red algal CaMK genes clustered into seven clades based on the maximum likelihood analysis of total 808 red algal copies (including 134 from G. chorda) and other eukaryotes. This results support that CaMK duplication may relate to the acquisition of complex signaling among cells along the red algal evolution.