| First Author | Ozawa M | Year | 1993 |
| Journal | J Biol Chem | Volume | 268 |
| Issue | 1 | Pages | 699-705 |
| PubMed ID | 8416973 | Mgi Jnum | J:26801 |
| Mgi Id | MGI:74232 | Doi | 10.1016/s0021-9258(18)54208-3 |
| Citation | Ozawa M, et al. (1993) Reticulocalbin, a novel endoplasmic reticulum resident Ca(2+)-binding protein with multiple EF-hand motifs and a carboxyl-terminal HDEL sequence. J Biol Chem 268(1):699-705 |
| abstractText | A novel Ca(2+)-binding protein, tentatively designated reticulocalbin, has been identified and characterized. Reticulocalbin is a luminal protein of the endoplasmic reticulum with an M(r) of 44,000 as revealed by biochemical analysis and immunofluorescence staining. The cDNA of reticulocalbin encodes a protein of 325 amino acids with an amino-terminal signal sequence of 20 amino acids. The protein has six repeats of a domain containing the high affinity Ca(2+)-binding motif, the EF-hand. Although oxygen-containing amino acids important for the positioning of Ca2+ are conserved in all six domains, the conserved glycine residues in the central portion of the EF-hand motif are absent in three of them. Calcium blots showed that recombinant reticulocalbin expressed in bacterial cells binds Ca2+. The protein has the sequence His-Asp-Glu-Leu (HDEL) at its carboxyl terminus. This is similar to the Lys-Asp-Glu-Leu sequence, which serves as a signal to retain the resident proteins in the endoplasmic reticulum of animal cells. A mutant protein lacking the HDEL sequence produced by in vitro mutagenesis has been shown to be secreted into medium in transient expression assays. |
