The tail domain is essential but the head domain dispensable for C. elegans intermediate filament IFA-2 function.

The intermediate filament protein IFA-2 is essential for the structural integrity of the Caenorhabditis elegans epidermis. It is one of the major components of the fibrous organelle, an epidermal structure comprised of apical and basal hemidesmosomes linked by cytoplasmic intermediate filaments that serve to transmit force from the muscle to the cuticle. Mutations of IFA-2 result in epidermal fragility and separation of the apical and basal epidermal surfaces during postembryonic growth.

SER-1, a Caenorhabditis elegans 5-HT2-like receptor, and a multi-PDZ domain containing protein (MPZ-1) interact in vulval muscle to facilitate serotonin-stimulated egg-laying.

Serotonin (5-HT) stimulation of egg-laying in Caenorhabditis elegans is abolished in ser-1 (ok345) animals and is rescued by ser-1 expression in vulval muscle. A PDZ binding motif (ETFL) at the SER-1 C-terminus is not essential for rescue, but facilitates SER-1 signaling. SER-1 binds specifically to PDZ domain 10 of the multi-PDZ domain protein, MPZ-1, based on GST pulldown and co-immunoprecipitation.

mua-6, a gene required for tissue integrity in Caenorhabditis elegans, encodes a cytoplasmic intermediate filament.

Locomotion in Caenorhabditis elegans requires force transmission through a network of proteins linking the skeletal muscle, via an intervening basal lamina and epidermis (hypodermis), to the cuticle. Mutations in mua-6 result in hypodermal rupture, muscle detachment from the bodywall, and progressive paralysis. It is shown that mua-6 encodes the cytoplasmic intermediate filament (cIF) A2 protein and that a MUA-6/IFA-2::GFP fusion protein that rescues the presumptive mua-6 null allele localizes to hypodermal hemidesmosomes.

Secretion of a novel developmentally regulated chitinase (family 19 glycosyl hydrolase) into the perivitelline fluid of the parasitic nematode, Ascaris suum.

The early development of the parasitic nematode, Ascaris suum, occurs within a chitinous eggshell and an abundant chitinase (As-p50) has been identified in the perivitelline fluid (PVF) surrounding the infective larva prior to hatching. A cDNA encoding As-p50 was cloned, sequenced and the protein expressed in Escherichia coli. As-p50 is a member of glycosyl hydrolase family 19, previously identified only in plants, making the characterization of As-p50 the first family 19 glycosyl hydrolase from any animal species.