Figure 1. Expression and Co-immunoprecipitation of HPS1Δex9.
(A) Top. Schematic representation of the HPS1 gene and location of the primers used for PCR analysis to detect HPS1 splice variants. Bottom. A panel of first-strand cDNAs derived from several human tissues (Clontech) was PCR amplified using a primer pair spanning exons 5–9. The two major transcripts were amplified as 766- bp (HPS1) and 667-bp (HPS1Δex9) fragments. β-Actin was utilized as loading control. Additional lower molecular weight bands reflect amplification of minor splice variants. (B) Stably transfected M1 cells expressing Myc3-HPS4 (clone number 26) were transiently transfected with constructs containing either HPS1 full-length or HPS1Δex9. An aliquot of these crude extracts corresponding to 1% of the material available for IP, was analyzed by immunoblotting (IB) using a mouse antibody against the V5 epitope and a mouse monoclonal antibody against the Myc tag. The crude extracts were used in immunoprecipitation (IP) reactions using a mouse monoclonal antibody against the Myc epitope. The immunoprecipitates were analyzed by 4–12% gradient SDS-PAGE followed by immunoblotting using a monoclonal antibody against the V5 epitope. The positions of molecular weight markers are indicated on the left.