Figure 1.

Expression of Recombinant Full-Length and Truncated SYP21.

(A) Schematic representation of the constructs used in this work. Either the full-length Arabidopsis SYP21 coding region or the sequence covering the first 251 amino acids comprising only the cytoplasmic domain was cloned under the transcriptional control of the CaMV35S promoter, generating the constructs full-length SYP21 and SYP21ΔTM, respectively. Shown is the orientation in the membrane and the typical domain structure of Q_A-SNAREs consisting of the transmembrane domain, the SNARE domain, and the three α-helical repeats Ha, Hb, and Hc.

(B) Protoplasts were transfected with a constant amount (30 μg) of plasmid encoding either full-length SYP21 (FL) or truncated SYP21 (ΔTM). After 24 h of incubation, cells were harvested. Protein extracts from entire protoplasts (total, left panel) and from soluble- or membrane-enriched fractions (right panel) were compared by protein gel blots and probed with anti-SYP21 antibodies. A mock-electroporated (−) sample was included to demonstrate the specificity of the antiserum. Molecular mass markers are indicated in kilodaltons.