Figure 2. Syntaxin 4 is a postsynaptic plasma membrane SNARE.

(A) Syx4 genomic region. Coding exons are indicated in green while non-coding exons are in blue. Two predicted start sites (ATG) are indicated in orange. The location of the P-element used for mutagenesis (P) is indicated in red. Three alleles of Syx4 were isolated. Deleted regions are indicated in red. Solid lines indicate regions known to be deleted from PCR analysis and sequencing, while dotted lines indicate regions within which breakpoints have been mapped. (B) Syx4 encodes a protein with an N-terminal domain, a SNARE domain and a C-terminal transmembrane domain. There are two predicted isoforms that differ in the size of the N-terminal domain. (C,D) Representative images of NMJs stained for Syx4 (green) and the neuronal membrane marker HRP (magenta). Syx4 staining at the synapse in precise excision control animals (C) is absent in Syx4⁷³ mutant animals (D). (E) Representative image from an animal stained for Syx4 (green) and expressing RFP-Syx4 (magenta) with 24B-GAL4. (F,G) Representative images from animals expressing Syt4-pH with 24B-GAL4 in a control (F) or Syx4⁷³ (G) background. Syt4-pH is reduced at the postsynaptic membrane and redistributed to large cytoplasmic accumulations in Syx4⁷³mutants. (F′,G′) Close-ups of F and G. (H,I) Representative images from Syt4^GFP-2M knock-in animals in a control (H) or Syx4⁷³ (I) background. Synaptic localization of Syt4^GFP-2M is reduced in Syx4⁷³mutants. (H′,I′) Close-ups of H and I. Scale bars = 5 μm (C–I), 2 μm (F′,G′,H′,I′).

DOI: http://dx.doi.org/10.7554/eLife.13881.007

Figure 2—figure supplement 1. RT-PCR analysis of Syntaxin 4.

Primers (red arrows) were designed to distinguish Syx4A and Syx4B transcripts by RT-PCR. F1 and R amplify a product from Syx4A transcript and F2 and R amplify a product from Syx4B transcript. Both transcripts are detected in control animals and both are absent from Syx4⁷³ nulls.

DOI: http://dx.doi.org/10.7554/eLife.13881.008