Cytoplasmic dynein participates in the centrosomal localization of the Golgi complex.

Abstract

The localization of the Golgi complex depends upon the integrity of the microtubule apparatus. At interphase, the Golgi has a restricted pericentriolar localization. During mitosis, it fragments into small vesicles that are dispersed throughout the cytoplasm until telophase, when they again coalesce near the centrosome. These observations have suggested that the Golgi complex utilizes a dynein-like motor to mediate its transport from the cell periphery towards the minus ends of microtubules, located at the centrosome. We utilized semi-intact cells to study the interaction of the Golgi complex with the microtubule apparatus. We show here that Golgi complexes can enter semi-intact cells and associate stably with cytoplasmic constituents. Stable association, termed here "Golgi capture," requires ATP hydrolysis and intact microtubules, and occurs maximally at physiological temperature in the presence of added cytosolic proteins. Once translocated into the semi-intact cell cytoplasm, exogenous Golgi complexes display a distribution similar to endogenous Golgi complexes, near the microtubule-organizing center. The process of Golgi capture requires cytoplasmic tubulin, and is abolished if cytoplasmic dynein is immunodepleted from the cytosol. Cytoplasmic dynein, prepared from CHO cell cytosol, restores Golgi capture activity to reactions carried out with dynein immuno-depleted cytosol. These results indicate that cytoplasmic dynein can interact with isolated Golgi complexes, and participate in their accumulation near the centrosomes of semi-intact, recipient cells. Thus, cytoplasmic dynein appears to play a role in determining the subcellular localization of the Golgi complex.

The Golgi Complex Is a Microtubule-organizing Organelle

“…Astral MTs seem indispensable for the reclustering of the organelle in a central location (Shima et al, 1998), but intermediate steps in this process might involve the capture of Golgiattached MTs in the centrosomal area to facilitate the reclustering process. Such a model would require Golgi MTs to exhibit reverse polarity or would be quite complicated in terms of molecular motor regulation, because Golgi reclustering is dynein dependent (Corthésy-Theulaz et al, 1992;Fath et al, 1994, Burkhardt et al, 1997Harada et al, 1998). This would be in a way similar to the behavior of chromosomes during mitosis because they have the possibility to directly nucleate MTs in addition to their capture by centrosomal MTs (Carazo-Salas et al, 1999).…”

“…Consistent with earlier findings by Feiguin et al (1994), who found that the expression of kinesin antisense oligonucleotide rendered the Golgi apparatus more compact, microinjection of antikinesin antibodies inhibited Golgi dispersion along stable, nocodazole-resistant MTs (Minin, 1997). Conversely, the central localization of the Golgi apparatus involves cytoplasmic dynein (Corthésy-Theulaz et al, 1992;Fath et al, 1994;Burkhardt et al, 1997;Harada et al, 1998). It is also worth noting that, in addition to the kinesin-mediated disruption of the central Golgi complex during MT depolymerization, the dispersion of Golgi elements also relies on the reconstitution of mini Golgi stacks at endoplasmic reticulum (ER) exit sites (Cole et al, 1996;Storrie et al, 1998).…”

The dynein genes of Paramecium tetraurelia: the structure and expression of the ciliary beta and cytoplasmic heavy chains.

“…Each heavy chain has two structural domains that perform distinct functions: the catalytic head domain, which contains the MgATPase and ATP-sensitive microtubule-binding activities; and the flexible dynein specialization occurs in the motor domain: all axonemal dyneins carry an outer doublet microtubule as their cargo, but each arm is specialized to generate precise mechanical force so that the dynein arms working together initiate and propagate ciliary bends (Asai and Brokaw, 1993;Brokaw, 1994). In contrast to axonemal dynein, cytoplasmic dynein carries a diverse array of molecular cargoes (Schnapp and Reese, 1989;Verde et al, 1991;Corthesy-Theulaz et al, 1992;Lin and Collins, 1992;Aniento et al, 1993;Vaisberg et al, 1993;Saunders et al, 1995;Wang et al, 1995) and is probably less specialized in force production. The current view is that cytoplasmic dynein is a homodimer of the heavy chain MAPlC (Vallee et al, 1988;Neely et al, 1990).…”

How the Golgi works: A cisternal progenitor model

“…The ability of the Golgi to undergo continuous, homotypic fusion can nevertheless be monitored by live-cell video microscopy after microinjection or fusion of two cell types harboring different colored Golgi stacks. Indeed, exogenously added, wild-type Golgi complexes could receive cargo from the Golgi complexes of mutant, semiintact CHO cells (35).…”