Hydrolethalus Syndrome Protein 1 (HYLS1)

The HYLS1 gene was predicted to encode a 299-amino acid polypeptide with an apparent molecular mass of 40 kD. Homologs were found in several species, including C. elegans, and the human coding region predicts 84% identity with the mouse protein. Immunohistochemical studies in mouse embryos revealed ubiquitous expression. Northern blot analysis of human tissues detected highest expression in brain, liver, lung, and kidney. The most common of several alternatively spliced transcripts is 1.7 kb long.Hyls1 interacted with Sas4 and was stably incorporated into centrioles as they formed via direct interaction with Sas4. Functional characterization of Hyls1 in C. elegans and Xenopus embryo ciliated epithelium revealed that Hyls1 was dispensable for centriole assembly and centrosome function, but that it was required for the formation of cilia.