21711401

not annotated - annotated - LINNAEUS only

Identification and characterization of the cysteine protease inhibitor gene MdCPI from Musca domestica.

Cysteine proteinase inhibitors (CPIs) are involved in many vital cellular processes such as signalling pathways, apoptosis, immune response and development; however, no CPIs have yet been reported from the housefly Musca domestica. Here we report the isolation and characterization of a housefly CPI gene designated MdCPI. The gene contains an open reading frame of 357 bp encoding a protein of 118 amino acid residues with a putative signal peptide of 17 amino acid residues. Protein alignment demonstrated a high homology to that of Sarcophaga crassipalpis (identity = 51%). Phylogenetic analysis suggested that all CPIs from dipterans, including the housefly, belong to the I25A family and may be descended from a single common ancestor. The gene was expressed in and purified from Escherichia coli. Biochemical studies showed that MdCPI exerts an inhibiting function on papain, which is a classical assay to confirm CPIs. Real-time quantitative PCR and immunolocalization analysis revealed that MdCPI is specifically expressed in haemocytes and fat bodies. It is highly down-regulated in larvae and markedly up-regulated in the pupal stage, suggesting that it may be related to development.



Ann file

T1	Species 87 102	Musca domestica

N1 Reference T1 Taxonomy:7370

T2 Species 312 320 housefly

N2 Reference T2 Taxonomy:7370

T3 Species 321 336 Musca domestica

N3 Reference T3 Taxonomy:7370

T4 Species 393 401 housefly

N4 Reference T4 Taxonomy:7370

T5 Species 641 664 Sarcophaga crassipalpis

N5 Reference T5 Taxonomy:59312

T6 Species 759 767 housefly

N6 Reference T6 Taxonomy:7370

T7 Species 891 907 Escherichia coli

N7 Reference T7 Taxonomy:562