p24/ING1-ALT1 and p47/ING1-ALT2, distinct alternative transcripts of p33/ING1

p33/ING1s (the growth inhibitor ING1 and candidate tumor suppressor ING1) are key players in the suppressive pathways for human tumorigenesis. We analyzed their complete transcripts, primary structures, and expression. The results led us to discover two novel and related alternatively spliced transcripts encoding p24/ING1-ALT1 and p47/ING1-ALT2. They share C-terminal residues with the candidate tumor suppressors p33/ING1. The candidate tumor suppressors p33/ING1 and p24/ING1-ALT1 were coexpressed in a variety of fetal and adult human tissues, but p47/ING1-ALT2 was minimally expressed.