Chlamydia trachomatis tarp is phosphorylated by src family tyrosine kinases.
The translocated actin recruiting phosphoprotein (Tarp) is injected into the cytosol shortly after Chlamydia trachomatis attachment to a target cell and subsequently phosphorylated by an unidentified tyrosine kinase. A role for Tarp phosphorylation in bacterial entry is unknown. In this study, recombinant C. trachomatis Tarp was employed to identify the host cell kinase(s) required for phosphorylation. Each tyrosine rich repeat of L2 Tarp harbors a sequence similar to a Src and Abl kinase consensus target. Furthermore, purified p60-src, Yes, Fyn, and Abl kinases were able to phosphorylate Tarp. Mutagenesis of potential tyrosines within a single tyrosine rich repeat peptide indicated that both Src and Abl kinases phosphorylate the same residues suggesting that C. trachomatis Tarp may serve as a substrate for multiple host cell kinases. Surprisingly, chemical inhibition of Src and Abl kinases prevented Tarp phosphorylation in culture and had no measurable effect on bacterial entry into host cells.
Jewett
Travis J
TJ
Host-Parasite Interactions Section, Laboratory of Intracellular Parasites, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rocky Mountain Laboratories, 903 South 4th Street, Hamilton, MT 59840, USA.
Dooley
Cheryl A
CA
Mead
David J
DJ
Hackstadt
Ted
T
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002692:Chlamydia trachomatis / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D008969:Molecular Sequence Data; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation; D017354:Point Mutation; D019061:src-Family Kinases / Q000378:metabolism*
D001426:Bacterial Proteins; D010750:Phosphoproteins; D019061:src-Family Kinases