| The rice blast disease, which results in significant annual rice yield losses worldwide, is the most destructive pathogen of cultivated rice worldwide. Recently, control measures like the use of resistant cultivars and application of fungicides have not allowed complete eradication of the disease. Consequently, the prevention and cure of rice blast disease is always an important problem in rice production. Important prerequisite for control of the disease is to know molecular regulation of growth and disease mechanisms. However, the availability of the genome sequences of both rice and the fungal pathogen have not only accelerated the discovery of pathogenesis related genes but also help research to find novel targets of chemical control and provide new sight and good idea for designing comprehensive management of Magnaporthe oryzae.Endocytosis is a fundamental cellular process in eukaryotic cells, which involves clathrin and adaptor proteins, various protein and lipid kinases, phosphatases, and the actin cytoskeleton.It is the process by which eukaryotic cells internalize plasma membrane (PM) lipids and associated proteins in vesicles that fuse with the endosomal system. Subsequent segregation into different endosomal domains determines whether a given cargo recycles to the PM, traffics to the Golgi or follows the endocytic pathway to the vacuolar lumen, thus undergoing degradation.In budding yeast, Edelp, an Eps15homology (EH) domain, which may function as an adaptor and plays a role in proper initation of endocytic sites, is the earliest protein known to arrive at endocytic sites. Accordingly, the recruitment of Sla2to endocytic sites seems to be an early endocytic event in yeast. Sla2is able to interact with other components of the endocytic machinery including Slal which is itself part of a complex that contains Panl and End3, which is important for endocytosis in yeast. Thus, endocytosis is a continuous process, which needs not only the recycling of a variety of substances but also reversible phosphorylation. In a large number of kinase family, the Ark/Prk serine/threonine protein kinase family has recently been shown to be important in controlling endocytosis and the actin cytoskeleton. Endocytosis, which is not well understood in fungi, have been shown to existence in the top of the filamentous mycelium. In M. oryzae, the mutantâ–³Mosec22andâ–³Movam7varying degrees affect the process of endocytosis. Based on that, in order to further understand the process of endocytosis in M. oryzae, we select Arkl and Panl is the object of study.We characterized an endocytosis kinase MoArkl, a homolog of Arklp in Saccharomyces cerevisiae, which appears to be encoded by a single copy gene and encodes a1021amino acid large protein. Like ScArklp, MoArkl possesses a potential S_TKc (Ser/thr kinase) in its N-termina, three phosphorylation sites and a conserved proline rich motif PxPPPKP in its C-terminal. Disruption of MoARK1resulted in hyposensitivity to various stresses, reduction in conidia formation, was defected in pathogenicity, mainly due to a penetration defect. Additionally, we showed that MoARK1is involved in cell wall integrity, formation of Spitzenkorper and endocytosis.Meanwhile, we characterized another endocytosis kinase MoPanl, a homolog of Panlp in S. cerevisiae, which appears to be encoded by a single copy gene and encodes a1462amino acid large protein. Like ScPanlp, MoPanl possesses a potential EH (Eps15Homology) domain in its N-terminal. Silencing of MoPAN1resulted in hyposensitivity to various stresses, reduction in conidia formation, was defected in pathogenicity. Additionally, we showed that MoPANl is involved in cell wall integrity and endocytosis. These results indicate that MoPANl functions as a an adaptor that plays a role in responses to endocytosis and cell wall integrity in M. oryzae. |
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