Calreticulin (CRT) is a highly conserved Ca2+-binding protein and chaperone in the endoplasmic reticulum, which mainly participates in adjusting calcium level and directing proper conformation of proteins. Here, we cloned the crt gene of the scleractinian coral Galaxea astreata, named Gacrt, and analysed its ability to drive bacterial agglutination. The full-length Gacrt cDNA consisted of 1 792 nucleotides and contained a 77 bp 5’ untranslated region (UTR), a 380 bp 3’ UTR and a 1 335 bp open reading frame (ORF) that encoded a 444 amino acid protein. The deduced peptide possessed a signal peptide domain, an endoplasmic reticulum retrieval signal sequence (KDEL), two potential calreticulin family signature motifs and a set of triplicate repeats. We also found that the recombinant GaCRT protein could promote agglutination of both the Gram-positive bacterium Micrococcus luteus and the Gram-negative bacterium Escherichia coli. These results show that the GaCRT protein can enhance bacterial agglutination, hinting that GaCRT is an immune-relevant molecule involved in host defense against bacterium.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |