Identification and molecular characterization of the alternative spliced variants of beta carbonic anhydrase 1 (βCA1) from Arabidopsis thaliana

Carbonic anhydrases (CAs) are ubiquitous zinc metalloenzymes that catalyze the interconversion of carbon dioxide and bicarbonate. Higher plants mainly contain the three evolutionarily distinct CA families alpha CA, beta CA, and gamma CA, with each represented by multiple isoforms. Alternative splicing (AS) of the CA transcripts is common. However, there is little information on the spliced variants of individual CA isoforms. In this study, we focused on the characterization of spliced variants of beta CA1 from Arabidopsis. The expression patterns and subcellular localization of the individual spliced variants of beta CA1 were examined. The results showed that the spliced variants of beta CA1 possessed different subcellular and tissue distributions and responded differently to environmental stimuli. Additionally, we addressed the physiological role of beta CA1 in heat stress response and its protein-protein interaction (PPI) network. Our results showed that beta CA1 was regulated by heat stresses, and beta ca1 mutant was hypersensitive to heat stress, indicating a role for beta CA1 in heat stress response. Furthermore, PPI network analysis revealed that beta CA1 interacts with multiple proteins involved in several processes, including photosynthesis, metabolism, and the stress response, and these will provide new avenues for future investigations of beta CA1.