Annotation inferences using phylogenetic trees

Gene Ontology annotation based on UniProtKB/Swiss-Prot Subcellular Location vocabulary mapping, accompanied by conservative changes to GO terms applied by UniProt

GO_REF:0000108

Automatic assignment of GO terms using logical inference, based on on inter-ontology links

PMID:11685578

Evolutionarily conserved nuclear migration genes required for early embryonic development in Caenorhabditis elegans.

RNAi knockdown of nud-1 causes embryonic lethality, sterility, altered vulval morphology, uncoordinated movement, and nuclear positioning defects in early embryonic cell division similar to dynein/dynactin depletion.

"Phenotypic analysis of either nud-1 and lis-1 by RNA interference yielded similar phenotypes, including embryonic lethality, sterility, altered vulval morphology, and uncoordinated movement."

PMID:16996038

Genetic interactions among cortical malformation genes that influence susceptibility to convulsions in C. elegans.

Depletion of NUD-1 and other LIS1 pathway components caused defective GABA synaptic vesicle trafficking and significant convulsions following pentylenetetrazole treatment.

"Worms depleted for LIS1 pathway components (NUD-1, NUD-2, DHC-1, CDK-5, and CDKA-1) exhibited significant convulsions following PTZ and RNAi treatment."

PMID:18626791

The microtubule-associated protein, NUD-1, exhibits chaperone activity in vitro.

Recombinant C. elegans NUD-1 prevents aggregation of citrate synthase and luciferase at stoichiometric concentrations, protects native CS from thermal inactivation, and maintains unfolded intermediates in a refolding-competent state. NUD-1 possesses ATP-independent chaperone activity comparable to small heat shock proteins.

"We demonstrate that nematode NUD-1 is able to prevent the aggregation of two substrate proteins, citrate synthase (CS) and luciferase, at stoichiometric concentrations."

PMID:12679384

Role for NudC, a dynein-associated nuclear movement protein, in mitosis and cytokinesis.

RNAi gene silencing of nud-1, the C. elegans ortholog of NudC, caused loss of midzone microtubules and rapid regression of the cleavage furrow, yielding one-celled embryos containing two nuclei - establishing a direct, worm-specific requirement for NUD-1 in midzone microtubule organization and completion of mitotic cytokinesis. In parallel mammalian cells, NudC depletion or overexpression caused multinucleation and disorganized midzone/midbody matrix and mislocalized polo-like kinase.

"Gene silencing of nud-1, the Caenorhabditis elegans ortholog of NudC, led to a loss of midzone microtubules and the rapid regression of the cleavage furrow, which resulted in one-celled embryos containing two nuclei."

file:worm/nud-1/nud-1-deep-research-falcon.md

Falcon deep research report on nud-1 (C. elegans)

The most defensible primary function of C. elegans NUD-1 is as an essential microtubule-based nuclear-positioning and cell-division factor acting in (i) pronuclear-centrosome rotation/positioning during the first embryonic division and (ii) midzone assembly and cleavage-furrow stabilization in cytokinesis. The nuclear-positioning phenotypes resemble dynein/dynactin perturbation, placing NUD-1 in the LIS-1/dynein nuclear-positioning pathway.

"essential microtubule-based cell division and nuclear-positioning factor"
In nud-1(RNAi) embryos, pronuclei moved inward but failed to rotate onto the anterior-posterior axis and nuclear envelope breakdown occurred on the dorsal-ventral axis, consistent with a dynein-associated role in pronuclear rotation/nuclear positioning rather than in initiating spindle elongation.

"pronuclei moved inward but failed to rotate onto the anterior-posterior axis; nuclear envelope breakdown occurred on the dorsal-ventral axis"
In nud-1 RNAi embryos, spindle elongation and pronuclear fusion proceeded but cleavage furrows stalled/regressed, producing multinucleated one-cell embryos; midzone microtubules were absent in 26% (10/39) and weak in 74% (29/39) of one-cell embryos, supporting a requirement for NUD-1 in late cytokinesis via midzone microtubule organization.

"Midzone microtubules were absent in 26% (10/39) of one-cell embryos and weak/poorly defined in 74% (29/39)"
nud-1 is the C. elegans nudC ortholog (cosmid F53A2, ORF F53A2.4); full-length nud-1, and especially its C-terminal 173 aa, complements the A. nidulans nudC3 mutant (47% identity / 67% similarity to A. nidulans NUDC), demonstrating deep functional conservation of the NudC family.

"Full-length `nud-1`, and especially its C-terminal 173 aa, complemented the *A. nidulans nudC3* mutant, restoring hyphal growth and nuclear migration"
NudC-family proteins have an N-terminal coiled-coil plus a conserved CS domain (related to p23 and HSP20/sHSP chaperones) and can function as Hsp70/Hsp90 co-chaperones that accelerate client transfer from Hsp70 to Hsp90. C. elegans NUD-1 specifically shows in vitro chaperone activity, preventing heat-induced aggregation of citrate synthase and luciferase. The co-chaperone/client biology is a family-level mechanistic model and is not directly demonstrated in vivo for the worm protein.

"NUD-1 is described as a microtubule-associated protein with in vitro chaperone activity, preventing heat-induced aggregation of citrate synthase and luciferase"