Kei1 is a subunit of Saccharomyces cerevisiae inositol phosphorylceramide (IPC) synthase [2]. It is localised to the Golgi and is cleaved by the late Golgi processing endopeptidase Kex2 [2]. Kei1 is essential for both the activity and the Golgi localization of IPC synthase [2].

1: Assigning function to yeast proteins by integration of technologies. Hazbun TR, Malmstrom L, Anderson S, Graczyk BJ, Fox B, Riffle M, Sundin BA, Aranda JD, McDonald WH, Chiu CH, Snydsman BE, Bradley P, Muller EG, Fields S, Baker D, Yates JR 3rd, Davis TN; Mol Cell 2003;12:1353-1365. PMID:14690591

2: Kei1: a Novel Subunit of Inositolphosphorylceramide Synthase, Essential for Its Enzyme Activity and Golgi Localization. Sato K, Noda Y, Yoda K; Mol Biol Cell. 2009; [Epub ahead of print] PMID:19726565