Maxwell G Heiman

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Cell fusion occurs throughout development, from fertilization to organogenesis. The molecular mechanisms driving plasma membrane fusion in these processes remain unknown. While yeast mating offers an excellent model system in which to study cell fusion, all genes previously shown to regulate the process act at or before cell wall breakdown; i.e., well(More)
Cells are devices whose structures delimit function. For example, in the nervous system, neuronal and glial shapes dictate paths of information flow. To understand how cells acquire their shapes, we examined the formation of a sense organ in C. elegans. Using time-lapse imaging, we found that sensory dendrites form by stationary anchoring of dendritic tips(More)
Under mating conditions, yeast cells adopt a characteristic pear-shaped morphology, called a "shmoo," as they project a cell extension toward their mating partners. Mating partners make contact at their shmoo tips, dissolve the intervening cell wall, and fuse their plasma membranes. We identified mutations in ERG4, encoding the enzyme that catalyzes the(More)
A dendrite grows by sprouting filopodia, some of which mature into stable dendrite branches that bear synapses and sprout filopodia of their own. Recent work has shown that a filopodium begins deciding to become a stable branch within 1min of contacting a presynaptic partner, but what triggers this decision remains unknown. We consider the evidence for(More)
The nematode Caenorhabditis elegans has a simple nervous system with glia restricted primarily to sensory organs. Some of the activities that would be provided by glia in the mammalian nervous system are either absent or provided by non-glial cell types in C. elegans, with only a select set of mammalian glial activities being similarly provided by(More)
Primary cilia are ubiquitous sensory organelles that mediate diverse signaling pathways. Cilia position on the cell surface is determined by the location of the basal body (BB) that templates the cilium. The mechanisms that regulate BB positioning in the context of ciliogenesis are largely unknown. Here we show that the conserved signaling and scaffolding(More)
The molecular machines that mediate cell fusion are unknown. Previously, we identified a multispanning transmembrane protein, Prm1 (pheromone-regulated membrane protein 1), that acts during yeast mating (Heiman, M.G., and P. Walter. 2000. J. Cell Biol. 151:719-730). Without Prm1, a substantial fraction of mating pairs arrest with their plasma membranes(More)
During development, biomechanical forces contour the body and provide shape to internal organs. Using genetic and molecular approaches in combination with a FRET-based tension sensor, we characterized a pulling force exerted by the elongating pharynx (foregut) on the anterior epidermis during C. elegans embryogenesis. Resistance of the epidermis to this(More)
A major goal in the study of human diseases is to assign functions to genes or genetic variants. The model organism Caenorhabditis elegans provides a powerful tool because homologs of many human genes are identifiable, and large collections of genetic vectors and mutant strains are available. However, the delivery of such vector libraries into mutant(More)
The ciliated receptive endings of sensory cells and the dendrites of other neurons are shaped by adhesive interactions, many of which depend on machinery also present in epithelia. Sensory cells are shaped by interactions with support cells through adhesion junctions via the Crumbs complex, tight junction components such as claudins, as well as interactions(More)