A yeast two hybrid screen identifies SPATA4 as a TRAPP interactor

The TRAPP vesicle-tethering complex consists of more than 10 distinct polypeptides and is involved in protein transport. Using the C2 subunit as bait we identified SPATA4, a spermatocyte-specific protein of unknown function, as an interacting partner in a yeast two hybrid screen. Further studies indicate SPATA4 interacts with the C2 portion of the TRAPP complex. SPATA4 fractionates with both cytosolic and nuclear fractions suggesting it may have several distinct functions. SPATA4 is one of only three human proteins that contain a DUF1042 domain and we show that C2 does not interact with another one of the DUF1042 domain-containing proteins. Our results suggest a role for SPATA4 in membrane traffic and a specialized function for TRAPP in spermatocytes.Structured summary of protein interactions:C2physically interacts with SPATA4 by two hybrid (View Interaction 1, 2)C2physically interacts with POSTN by two hybrid(View interaction)C2Lphysically interacts with REPS2 by two hybrid(View interaction)C2Lphysically interacts with TRAPPC3 by two hybrid(View interaction)C2physically interacts with LAP3 by two hybrid(View interaction)C2physically interacts with SPATA4 by anti bait coimmunoprecipitation(View interaction)C2Lphysically interacts with SPATA22 by two hybrid(View interaction)SPATA4, C2 and C3colocalize by cosedimentation through density gradient(View interaction)SPATA4binds to C2 by pull down(View interaction)C2physically interacts with TRAPPC3 by two hybrid(View interaction)C2Lphysically interacts with SPATA4 by anti tag coimmunoprecipitation(View interaction)C2physically interacts with REPS2 by two hybrid(View interaction)SPATA4 and C2physically interact by molecular sieving(View interaction)C2Lphysically interacts with LAP3 by two hybrid(View interaction)C2physically interacts with SPATA22 by two hybrid(View interaction)C2Lphysically interacts with POSTN by two hybrid(View interaction)

► A yeast two-hybrid screen identified SPATA4 as a TRAPPC2 interacting partner.
► SPATA4 binds to C2 in vitro when it is part of a TRAPP subcomplex.
► The carboxy-terminus of C2, often mutated in SEDT, is essential for its interaction with SPATA4.
► Only the cytosolic pool of SPATA4 binds to TRAPP.
► SPATA4, a protein of unknown function, may play a role in membrane traffic in spermatocytes.