Assaying Rho GTPase-Dependent Processes in Dictyostelium discoideum.

The model organism D. discoideum is well suited to investigate basic questions of molecular and cell biology, particularly those related to the structure, regulation, and dynamics of the cytoskeleton, signal transduction, cell-cell adhesion, and development. D.

The membrane-associated fraction of cyclase associate protein 1 translocates to the cytosol upon platelet stimulation.

Platelets undergo profound shape changes upon adhesion to damaged blood vessel walls that are mediated by reorganisation of the actin cytoskeleton in response to receptor-mediated signalling cascades. The highly conserved 56 kDa multidomain cyclase associated protein 1 (CAP1) works in concert with cofilin and profilin to modulate actin filament turnover by facilitating cofilin-mediated actin filament severing and depolymerisation and catalysing profilin-mediated regeneration of actin monomers for reutilisation in growing filaments. CAP1 is abundant in platelets but its roles remain unexplored.

An enhanced C. elegans based platform for toxicity assessment.

There is a well-defined regulatory framework governing the approval of chemicals for use as pharmaceuticals or release into the environment. Toxicity assessment is thus a major hurdle in the compound discovery pipeline, currently involving large scale animal testing. The search for alternative testing platforms is therefore an important priority.

Rho Signaling in Dictyostelium discoideum.

Small GTPases of the Rho family are ubiquitous molecular switches involved in the regulation of most actin cytoskeleton dependent processes and many other processes not directly linked to actin. D. discoideum is a well-established model organism for studies of the actin cytoskeleton and its regulation by signal transduction pathways.

Assaying Rho GTPase-dependent processes in Dictyostelium discoideum.

The model organism D. discoideum is well suited to investigate basic questions of molecular and cell biology, particularly those related to the structure, regulation, and dynamics of the cytoskeleton, signal transduction, cell-cell adhesion, and development. D.

The branched actin nucleator Arp2/3 promotes nuclear migrations and cell polarity in the C. elegans zygote.

Regulated movements of the nucleus are essential during zygote formation, cell migrations, and differentiation of neurons. The nucleus moves along microtubules (MTs) and is repositioned on F-actin at the cellular cortex. Two families of nuclear envelope proteins, SUN and KASH, link the nucleus to the actin and MT cytoskeletons during nuclear movements.

CP250, a novel acidic coiled-coil protein of the Dictyostelium centrosome, affects growth, chemotaxis, and the nuclear envelope.

The Dictyostelium centrosome is a nucleus associated body consisting of a box-shaped core surrounded by the corona, an amorphous matrix functionally equivalent to the pericentriolar material of animal centrosomes which is responsible for the nucleation and anchoring of microtubules. Here we describe CP250 a component of the corona, an acidic coiled coil protein that is present at the centrosome throughout interphase while disappearing during prophase and reappearing at the end of late telophase. Amino acids 756-1148 of the 2110 amino acids are sufficient for centrosomal targeting and cell cycle-dependent centrosome association.

Dictyostelium Sun-1 connects the centrosome to chromatin and ensures genome stability.

The centrosome-nucleus attachment is a prerequisite for faithful chromosome segregation during mitosis. We addressed the function of the nuclear envelope (NE) protein Sun-1 in centrosome-nucleus connection and the maintenance of genome stability in Dictyostelium discoideum. We provide evidence that Sun-1 requires direct chromatin binding for its inner nuclear membrane targeting.