RESUMO
Protein kinase C-δ (PKC-δ) is an important protein in the immune system of higher vertebrates. Lampreys, as the most primitive vertebrates, have a uniquevariable lymphocyte receptor (VLR) immune system. PKC-δ-like is a crucial functional gene in lampreys and is highly expressed in their immune organs. In this study, lampreys were stimulated with different immunogens, and lipopolysaccharide (LPS) was found to increase the expression of PKC-δ-like. Overexpression of PKC-δ-like could also effectively activate the innate immune response. We further demonstrated that PKC-δ-like-CF, a catalytic fragment of PKC-δ-like, is responsible for activating the innate immune response, and Thr-211, which is Thr-419 of PKC-δ-like, was confirmed to be the key site affecting PKC-δ-like-CF activity. These results indicated that PKC-δ-like from lamprey may have an important role in the innate immune response.
Assuntos
Lampreias/metabolismo , Proteína Quinase C-delta/metabolismo , Animais , Imunidade Inata/fisiologia , Inflamação/imunologia , Inflamação/metabolismo , Lipopolissacarídeos/farmacologia , Masculino , Camundongos , Células RAW 264.7RESUMO
CDK-2, a member of the cyclin-dependent kinase family, plays an important role in many cell processes, such as cell cycle regulation, cell growth and differentiation, and cell apoptosis. Lampreys belong to the most primitive vertebrates, and there is no report about the CDK-2 gene in lampreys at present. In this study, a CDK-2-like gene sequence and deduced amino acid sequence were identified in Japanese lamprey (Lampetra japonica, L. japonica). The CDK-2-like gene has about 80% similarity with its homologs in jaw vertebrates. The polyclonal antibody against CDK-2-like was well prepared, and the results showed that CDK-2-like was highly expressed in the gonad tissue of lampreys. Apoptosis could reduce the expression of CDK-2-like in lymphocytes of lamprey, while overexpression of CDK-2-like could inhibit apoptosis. In addition, inhibition of CDK-2-like activity was able to trigger out apoptosis and also helped apoptotic inducer actinomycin D (Act-D) to induce apoptosis. These results suggest that CDK-2-like identified from lamprey may play a crucial role in apoptosis of jawless vertebrates.