Characterization and expression analysis of two human septin genes, PNUTL1 and PNUTL2.

The presence and role of septin proteins in yeast is well documented, but there is a growing appreciation for this family of proteins beyond yeast and extending to human cells. In this report we present the characterization and comparison of two highly similar human septin genes, PNUTL1 and PNUTL2. We compare the exon/intron structure of both genes, the steady-state mRNA levels in tumor cell lines and adult organs, the conceptual translation products from alternatively processed mRNAs and the development of specific immunologic reagents distinguishing either PNUTL1 or PNUTL2. The results illustrate a remarkable similarity between the two genes and their protein products while identifying specific differences in mRNA expression patterns. A summary of the described functional roles for mammalian septins is discussed along with an attempt to assimilate the alternative nomenclature existing for the same human septins, such as references to PNUTL1 and PNUTL2 as hCDCrel-1 and hCDCrel-2, respectively. The characterization of PNUTL1 and PNUTL2 represents a fundamental step in completing the characterization of the entire family of human septin genes.