Structural highlights
Function
TMED2_HUMAN Involved in vesicular protein trafficking. Mainly functions in the early secretory pathway but also in post-Golgi membranes. Thought to act as cargo receptor at the lumenal side for incorporation of secretory cargo molecules into transport vesicles and to be involved in vesicle coat formation at the cytoplasmic side. In COPII vesicle-mediated anterograde transport involved in the transport of GPI-anchored proteins and proposed to act together with TMED10 as their cargo receptor; the function specifically implies SEC24C and SEC24D of the COPII vesicle coat and lipid raft-like microdomains of the ER. Recognizes GPI anchors structural remodeled in the ER by PGAP1 and MPPE1. In COPI vesicle-mediated retrograde transport inhibits the GTPase-activating activity of ARFGAP1 towards ARF1 thus preventing immature uncoating and allowing cargo selection to take place. Involved in trafficking of G protein-coupled receptors (GPCRs). Regulates F2RL1, OPRM1 and P2RY4 exocytic trafficking from the Golgi to the plasma membrane thus contributing to receptor resensitization. Facilitates CASR maturation and stabilization in the early secretory pathway and increases CASR plasma membrane targeting. Proposed to be involved in organization of intracellular membranes such as the maintenance of the Golgi apparatus. May also play a role in the biosynthesis of secreted cargo such as eventual processing.[1] [2] [3] [4] [5]
Publication Abstract from PubMed
The p24 family consists of four subfamilies (p24alpha, p24beta, p24gamma, and p24delta), and the proteins are thought to form hetero-oligomeric complexes for efficient transport of cargo proteins from the endoplasmic reticulum to the Golgi apparatus. The proteins possess a conserved luminal Golgi dynamics (GOLD) domain, whose functions are largely unknown. Here, we present structural and biochemical studies of p24beta1 and p24delta1 GOLD domains. Use of GOLD domain-deleted mutants revealed that the GOLD domain of p24delta1 is required for proper p24 hetero-oligomeric complex formation and efficient transport of GPI-anchored proteins. The p24beta1 and p24delta1 GOLD domains share a common beta-sandwich fold with a characteristic intrasheet disulfide bond. The GOLD domain of p24delta1 crystallized as dimers, allowing the analysis of a homophilic interaction site. Surface plasmon resonance and solution NMR analyses revealed that p24beta1 and p24delta1 GOLD domains interact weakly (Kd= ~10-4M). Bi-protein titration provided interaction site maps. We propose that the heterophilic interaction of p24 GOLD domains contributes to the formation of the p24 hetero-oligomeric complex and to efficient cargo transport.
3D Structure and Interaction of p24beta and p24delta Golgi Dynamics Domains: Implication for p24 Complex Formation and Cargo Transport.,Nagae M, Hirata T, Morita-Matsumoto K, Theiler R, Fujita M, Kinoshita T, Yamaguchi Y J Mol Biol. 2016 Aug 25. pii: S0022-2836(16)30342-4. doi:, 10.1016/j.jmb.2016.08.023. PMID:27569046[6]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Goldberg J. Decoding of sorting signals by coatomer through a GTPase switch in the COPI coat complex. Cell. 2000 Mar 17;100(6):671-9. PMID:10761932
- ↑ Luo W, Wang Y, Reiser G. p24A, a type I transmembrane protein, controls ARF1-dependent resensitization of protease-activated receptor-2 by influence on receptor trafficking. J Biol Chem. 2007 Oct 12;282(41):30246-55. Epub 2007 Aug 10. PMID:17693410 doi:http://dx.doi.org/10.1074/jbc.M703205200
- ↑ Stepanchick A, Breitwieser GE. The cargo receptor p24A facilitates calcium sensing receptor maturation and stabilization in the early secretory pathway. Biochem Biophys Res Commun. 2010 Apr 23;395(1):136-40. doi:, 10.1016/j.bbrc.2010.03.156. Epub 2010 Mar 31. PMID:20361938 doi:http://dx.doi.org/10.1016/j.bbrc.2010.03.156
- ↑ Bonnon C, Wendeler MW, Paccaud JP, Hauri HP. Selective export of human GPI-anchored proteins from the endoplasmic reticulum. J Cell Sci. 2010 May 15;123(Pt 10):1705-15. doi: 10.1242/jcs.062950. Epub 2010, Apr 27. PMID:20427317 doi:http://dx.doi.org/10.1242/jcs.062950
- ↑ Luo W, Wang Y, Reiser G. Proteinase-activated receptors, nucleotide P2Y receptors, and mu-opioid receptor-1B are under the control of the type I transmembrane proteins p23 and p24A in post-Golgi trafficking. J Neurochem. 2011 Apr;117(1):71-81. doi: 10.1111/j.1471-4159.2011.07173.x. Epub, 2011 Feb 9. PMID:21219331 doi:http://dx.doi.org/10.1111/j.1471-4159.2011.07173.x
- ↑ Nagae M, Hirata T, Morita-Matsumoto K, Theiler R, Fujita M, Kinoshita T, Yamaguchi Y. 3D Structure and Interaction of p24beta and p24delta Golgi Dynamics Domains: Implication for p24 Complex Formation and Cargo Transport. J Mol Biol. 2016 Aug 25. pii: S0022-2836(16)30342-4. doi:, 10.1016/j.jmb.2016.08.023. PMID:27569046 doi:http://dx.doi.org/10.1016/j.jmb.2016.08.023
