Eps15 Research Articles

Rac1 and EMT: a dangerous liaison?

Rac1 was originally identified in 1989 in human platelets as a substrate of the botulinum toxin from which its name derives: Ras-related C3 botulinum toxin substrate (1). Rac1 belongs to the Rho family of small guanosine triphosphatases (GTPases), and is ubiquitously expressed. It exists in two conformational states, an inactive GDP-bound form and an active GTP-bound form. The transition from one form to another occurs upon stimuli and depends on GTPase-activating proteins (GAPs), which inactivate Rac1, and guanine nucleotide exchange factors (GEFs), which convert Rac1 to its active form. Among GEFs, the trimeric complex SOS1/EPS8/ABI1 plays a role in Rac regulation. Dissection of the complex shows that SOS1 is central because it supports the catalytic component of the complex, and both ABI1, also named EPS8 SH3 domain binding protein, and EPS8 with its SOS1 binding domain, allow the cohesion of this complex. Functionally, Rac1 was the subject of numerous studies highlighting diverse and broad cellular functions since its discovery. Rac1 serves as a conformational switch in several signal transduction pathways at the origin of its biological functions. One of its primary function identified, far away the most characterized, is the regulation of actin cytoskeleton organization and dynamics, in the migratory structures such as filopodia and lamellipodia. Subsequently, other Rac1 functions were evidenced including roles in cell polarity, gene expression, cell-cycle progression, and cell survival.

Isolation of salt-inducible genes related to signal transduction in barley by differential display

To survive under environmental stresses, plant developed signal transduction systems. It is important how quickly and efficiently plants sense outer stimuli. However the information involved in signal transductions under salt stress is still limited. In this work we isolated the candidates of salt-stress responsive genes related to signal transductions in barley by differential display. About 30 candidates belong to protein kinase family (MAP kinase, PIP5 kinase, casein kinase, putative serine/ threonine protein kinase, receptor protein kinase, etc.), protein phosphatase and transcription factors (putative SET-domain transcriptional regulator). Among them, one candidate has homology to human EPS15. EPS15 has an EH-domain and interacts with EPS receptor in animal cell. EPS receptor catches certain ligands from out of the cell and then transduces the signal into inner membrane. The interactions between EPS15 and EPS receptor mediated by tyrosine phospholyration are implicated in endocytosis and synaptic vesicle recycling. This is to our knowledge the first report of the relationship between plant salt stress and endocytosis.

Gene cloning and characterization of salt-inducible aldehyde oxidase in barley

To survive under environmental stresses, plant developed signal transduction systems. It is important how quickly and efficiently plants sense outer stimuli. However the information involved in signal transductions under salt stress is still limited. In this work we isolated the candidates of salt-stress responsive genes related to signal transductions in barley by differential display. About 30 candidates belong to protein kinase family (MAP kinase, PIP5 kinase, casein kinase, putative serine/ threonine protein kinase, receptor protein kinase, etc.), protein phosphatase and transcription factors (putative SET-domain transcriptional regulator). Among them, one candidate has homology to human EPS15. EPS15 has an EH-domain and interacts with EPS receptor in animal cell. EPS receptor catches certain ligands from out of the cell and then transduces the signal into inner membrane. The interactions between EPS15 and EPS receptor mediated by tyrosine phospholyration are implicated in endocytosis and synaptic vesicle recycling. This is to our knowledge the first report of the relationship between plant salt stress and endocytosis.

Solution structure of the apo EH1 domain of mouse Eps15

Solution structure of the apo EH1 domain of mouse Eps15