Novel Promoters for Human NAIP Figure 5. Detection of novel NAIP protein isoforms. A) Diagrams of NAIPfull (top) and NAIP1/2 (bottom) are shown; speckled exons 12–14 are only encoded by NAIP2 in the reference human genome. The known NAIP TSS are indicated by bent arrows, and computational translation predicts the domain composition and mass of the resulting ORFs: NAIPfull, NAIPAlu, NAIP1/2. NAIP1 is predicted to encode a ,100 kDa protein, and NAIP2 is ,130 kDa. The BIRs (Baculoviral IAP Repeat); NBD (Nucleotide binding domain) and LRR (Leucine-rich repeat) domains are indicated by circles, cylinders, and triangles respectively. B) Western blot of NAIP in PC3, HeLa, and NTera2D1. Endogenous expression of NAIPfull, NAIP2, NAIPAlu, and NAIP1 (top) and HA-tagged NAIPAlu (bottom) is shown in transfected and untransfected cells. doi:10.1371/journal.pone.0005761.g005 Figure 6. Expression of NAIP protein isoforms in primary human tissues. Western blot analysis of a commercial, pre-transferred membrane with human proteins deriving from the tissues of one adult female, with the exception of testis. NAIP expression is shown at top, and actin levels at bottom. Mass of bands is indicated at left. doi:10.1371/journal.pone.0005761.g006 PLoS ONE | www.plosone.org 7 June 2009 | Volume 4 | Issue 6 | e5761