stn, stoned, stn-B
Gene model reviewed during 5.53
gene_with_dicistronic_mRNA ; SO:0000722
Gene model reviewed during 5.52
Gene model reviewed during 5.54
8.4 (northern blot)
1260 (aa); 138 (kD observed)
Interacts with the second C2 domain of Syt.
The Asn-Pro-Phe (NPF) motifs, which are found in proteins involved in the endocytic pathway, are known to interact with the EH domain.
Click to get a list of regulatory features (enhancers, TFBS, etc.) and gene disruptions (point mutations, indels, etc.) within or overlapping Dmel\stnB using the Feature Mapper tool.
GBrowse - Visual display of RNA-Seq signalsView Dmel\stnB in GBrowse 2
Please Note This section lists cDNAs and ESTs that fall within the genomic extent of the gene model, which may include cDNAs and ESTs of genes within introns, or of overlapping genes. Please see GBrowse for alignment of the cDNAs and ESTs to the gene model.
For each fully sequenced cDNA the DGRC maintains various forms of the cDNA (e.g tagged or untagged) in several different host vectors for subsequent cloning and expression in Drosophila and Drosophila cell lines.
Rescue analysis suggests that the stnB open reading frame (ORF) encodes all vital and important functions of the dicistronic "stn" locus and that the stnA ORF encodes a dispensible protein. However, this interpretation is limited by the absence of a true null for "stn" due to partial rescue of presynaptic stnA protein by transgenically provided stnB protein.
Neuronal expression of a dicistronic "stn" transcript (encoding both stnA and stnB proteins) is sufficient to rescue various phenotypic defects of "stn" mutants, including lethality and defects in evoked transmitter release and syt protein localisation at the nerve terminals. In addition, neural expression of a monocistronic stnB transgene is sufficient to rescue all these defects. In contrast, neural expression of a monocistronic stnA transgene does not rescue any of the "stn" mutant phenotypes. In addition, "stn" is required for regulating normal growth and morphology of the motor terminal, and this function is also provided by a monocistronic stnB transgene.
"stn" mutants show a striking decrease in the size of the endo-exo-cycling synaptic vesicle pool and loss of spatial regulation of the vesicular recycling intermediates. Mutant synapses display a significant delay in vesicular membrane retrieval after depolarisation and neurotransmitter release.
The 'stoned' locus produces a dicistronic transcript and encodes two distinct polypeptides. The structure of the protein encoded by the stnB ORF suggests a possible role in membrane trafficking, allowing an interpretation of the interaction seen between temperature sensitive 'stoned' and shi mutants.