Psychiatry related information on unc-4

• Experiments with a temperature-sensitive unc-4 mutant show that the adult level of SV proteins strictly depends on unc-4 function during a critical period of motor neuron differentiation. unc-4 activity during this sensitive larval stage is also required for the creation of proper synaptic inputs to VA motor neurons [1].

High impact information on unc-4

• Mutations in the Caenorhabditis elegans unc-4 gene alter the synaptic input to ventral cord motor neurons [2].
• We show that the absence of a functional unc-4 gene product accounts for the mutant phenotype [3].
• A compensatory amino acid substitution in UNC-37 suppresses specific unc-4 alleles by restoring physical interactions with UNC-4 as well as UNC-4-dependent repression of VB-specific genes [4].
• The amino acid sequence of the mouse Uncx-4.1 homeodomain is closely related to the sequence of the unc-4 homeodomain of Caenorhabditis elegans [5].
• Finally, the expression patterns of three neuronal type-specific transcription factors, unc-3, unc-4 and unc-30, were altered [6].

Biological context of unc-4

• We have isolated four, dominant, extragenic, allele-specific suppressors of unc-4(e2322ts), a temperature sensitive allele with a point mutation in the unc-4 homeodomain [7].
• Both genes, which are separated by 250,000 to 300,000 base-pairs were assigned to chromosome II by in situ hybridization and physically linked to a DNA polymorphism located near unc-4 on the genetic map [8].
• Our results are consistent with a model in which this unc-4 target gene ("gene-x") functions at a post-transcriptional level as a negative regulator of SV biogenesis or stability [1].
• A novel Drosophila paired-like homeobox gene related to Caenorhabditis elegans unc-4 is expressed in subsets of postmitotic neurons and epidermal cells [9].

Anatomical context of unc-4

• The normal function of the wild-type allele of unc-4 may thus be to invoke the appropriate synaptic specificities to VA motor neurons produced in particular developmental contexts [2].
• We propose that unc-4 controls a differentiated characteristic of the VA motor neurons that distinguishes them from their VB sisters, thus dictating recognition by the appropriate interneurons [10].

Associations of unc-4 with chemical compounds

• The remaining three mutants (unc-4, cha-1, and unc-17) are defective for synthesis or packaging of acetylcholine in the VCs [11].

Physical interactions of unc-4

• Alternatively, unc-37 may encode a gene product that interacts with the unc-4 homeodomain [7].

Regulatory relationships of unc-4

• We propose that unc-37 may be regulated by unc-4 [7].

Other interactions of unc-4

• The Groucho-like transcription factor UNC-37 functions with the neural specificity gene unc-4 to govern motor neuron identity in C. elegans [12].
• We show that expression of a functional unc-4-beta-galactosidase chimeric protein in VA motor neurons restores wild-type movement to an unc-4 mutant [10].

References