Identification of candidate sialome components expressed in ixodid tick salivary glands using secretion signal complementation in mammalian cells.
Ixodid ticks manipulate mammalian host pathways by secreting molecules from salivary glands. Novel cDNAs containing functional secretion signals were isolated from ixodid tick salivary glands using a signal sequence trap. Only 15/61 Rhipicephalus appendiculatus and 1/7 Amblyomma variegatum cDNAs had significant identity (< 1e-15) to previously identified sequences. Polypeptides that may interact with host pathways included a kinase inhibitor. Two proteins encoded homologues of the yolk protein vitellogenin and seventeen contained glycine-rich motifs. Four proteins without sequence matches had conserved structural folds, identified using a Threading algorithm. Predicted secretion signals were between fifteen and fifty-seven amino acids long. Four homologous polymorphic proteins contained conserved (26/27 residues) signal peptides. Ten functional tick secretion signals could not be unambiguously identified using predictive algorithms.
Lambson
B
B
The International Livestock Research Institute (ILRI), Nairobi, Kenya.
Nene
V
V
Obura
M
M
Shah
T
T
Pandit
P
P
Ole-Moiyoi
O
O
Delroux
K
K
Welburn
S
S
Skilton
R
R
de Villiers
E
E
Bishop
R
R
D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D019556:COS Cells; D002522:Chlorocebus aethiops; D017124:Conserved Sequence; D005260:Female; D019476:Insect Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D026863:Ixodidae / Q000235:genetics / Q000502:physiology*; D008969:Molecular Sequence Data; D021382:Protein Sorting Signals / Q000235:genetics / Q000502:physiology*; D012333:RNA, Messenger / Q000737:chemistry / Q000235:genetics; D019105:Random Amplified Polymorphic DNA Technique; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012471:Salivary Proteins and Peptides / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D016415:Sequence Alignment; D014162:Transfection
D019476:Insect Proteins; D021382:Protein Sorting Signals; D012333:RNA, Messenger; D012471:Salivary Proteins and Peptides