PalH (also known as RIM21) is a transmembrane protein required for proteolytic cleavage of Rim101/PacC transcription factors which are activated by C terminal proteolytic processing. Rim101/PacC family proteins play a key role in pH-dependent responses and PalH has been implicated as a pH sensor [1].

1: Arrestin-related proteins mediate pH signaling in fungi. Herranz S, Rodriguez JM, Bussink HJ, Sanchez-Ferrero JC, Arst HN Jr, Penalva MA, Vincent O; Proc Natl Acad Sci U S A. 2005;102:12141-12146. PMID:16099830

2: Relationship of DFG16 to the Rim101p pH response pathway in Saccharomyces cerevisiae and Candida albicans. Barwell KJ, Boysen JH, Xu W, Mitchell AP; Eukaryot Cell. 2005;4:890-899. PMID:15879523