Journal of Cell Science 116, e501-e501 (2003)
Copyright © 2003 The Company of Biologists Limited
Adaptors for TGN transport
Transport between the trans-Golgi network (TGN) and endosomes takes place
in clathrin-coated vesicles (CCVs). The clathrin-adaptor protein AP-1 and
members of the GGA protein family are essential adaptors in this process, but
do they act in concert, in parallel or in opposite directions? In a Commentary
on p. 763, Ina Hinners and
Sharon Tooze discuss the structure and function of these adaptors and try to
answer this question. Early work suggested that AP-1 complexes form at the TGN
and function in TGN-to-endosome (anterograde) transport. The observation that
cargo molecules do not get stuck at the TGN in mice lacking an AP-1 subunit
cast doubt on this idea; GGA proteins instead were proposed to regulate
anterograde transport, since they interact with clathrin and compromise
anterograde transport when mutated. GGA proteins interact with AP-1, however,
and are not stable components of CCVs. Hinners and Tooze therefore argue that
both adaptors function in anterograde transport. They propose that transient
association of GGA proteins with CCVs recruits AP-1 during anterograde
transport but that AP-1 is also part of a distinct retrograde transport
mechanism.
Related articles in JCS:
- Changing directions: clathrin-mediated transport between the Golgi and endosomes
- Ina Hinners and Sharon A. Tooze
JCS 2003 116: 763-771.
[Abstract]
[Full Text]
