Lorenzon-Ojea, Aline R.
Ribeiro, Alberto F.
Fisher, Susan J.
Guzzo, Cristiane R.
Total Authors: 6
 Univ Sao Paulo, Inst Biomed Sci, Dept Cell & Dev Biol, Sao Paulo - Brazil
 Univ Sao Paulo, Dept Genet & Evolutionary Biol, Inst Biosci, Sao Paulo - Brazil
 Univ Calif San Francisco, Sch Med, Dept Obstet Gynecol & Reprod Sci, San Francisco, CA - USA
 Univ Sao Paulo, Inst Biomed Sci, Dept Microbiol, Sao Paulo - Brazil
Total Affiliations: 4
INTERNATIONAL JOURNAL OF BIOCHEMISTRY & CELL BIOLOGY;
Web of Science Citations:
The stromal derived factor (SDFs) family comprises a group of molecules generated by stromal cells. SDF1 and SDF4 are chemokines; SDF2 and SDF5 are not yet functionally and structurally defined. In human and mouse, Sdfl has a paralogous gene, Sdf2l1, whose protein sequences are 78% similar and 68% identical. Human SDF2L1 is an endoplasmic reticulum-stress inducible-gene. In Arabidopsis thaliana, SDF2-like (39% and 37% amino acid sequence identity with Mus musculus Sdf2 and Sdf2l1) has also been implicated in activating the UPR in ER-stress. Here we have cloned, expressed and purified recombinant Sdf2 and raised an anti-Sdf2 antibody. We demonstrated that the protein is expressed in several tissues and is localized in the endoplasmic reticulum. We suggest that Sdf2, initially predicted as a secretory protein because it lacks the canonical ER retention signals in its C-terminal, could be ER-resident through accessory binding proteins or other amino acid sequence motifs, as suggested for the homolog protein SDF2-like. Furthermore, the crystal structure of SDF2-like from Arabidopsis thaliana is a typical beta-trefoil containing three MIR motifs; all hydrophobic residues considered important for maintaining the bottom layer of the beta-trefoil barrel seem to be conserved in the Sdf2 family. Multiple alignment using 43 sequences for SDF2 and 38 for SDF2L1 paralogous families also revealed a very similar residue conservation profile. Comparing the amino acid sequence and predicted 3D structure with other Sdf2-like proteins we suggest a role of mouse Sdf2 in the Unfolded Protein Response and ER-stress, similar to that of Sdf2l1 from human and mouse and SDF2-like from Arabidopsis thaliana. Chronic ER stress has been associated with many human diseases including cancer and diabetes. Identification of new factors associated with the ER stress pathway can help to identify and define key targets of this response. (C) 2014 Elsevier Ltd. All rights reserved. (AU)