Tyrosine O-sulfation is one of the post-translational modification processes that occur to membrane proteins and secreted proteins in eukaryotes. Tyrosylprotein sulfotransferase (TPST) is responsible for this modification, and in this report, we describe the expression pattern and the biological role of TPST-A in the nematode Caenorhabditis elegans. We found that TPST-A was mainly expressed in the hypodermis, especially in the seam cells. Reduction of TPST-A activity by RNAi caused severe defects in cuticle formation, indicating that TPST-A is involved in the cuticle formation in the nematode. We found that RNAi of TPST-A suppressed the roller phenotype caused by mutations in the rol-6 collagen gene, suggesting that sulfation of collagen proteins may be important for proper organization of the extracellular cuticle matrix. The TPST-A RNAi significantly decreased the dityrosine level in the worms, raising the possibility that the sulfation process may be a pre-requisite for the collagen tyrosine cross-linking.
Bibliographical noteFunding Information:
We thank Dr. Injae Shin and Myung-ryul Lee for the purification of dityrosine (Department of chemistry, University of Yonsei, Seoul, Korea), Caenorhabditis Genetics Center for providing strains, and Dr. Yuji Kohara for providing the cDNA clone. This research was supported by the KOSEF through the center for Protein Network Research Center (PNRC) at Yonsei University (R11200007802001).
All Science Journal Classification (ASJC) codes
- Structural Biology
- Molecular Biology
- Cell Biology