5crv | pdb_00005crv
Crystal structure of the Bro domain of HD-PTP in a complex with the core region of STAM2
Structural highlights
Function[PTN23_HUMAN] Plays a role in sorting of endocytic ubiquitinated cargos into multivesicular bodies (MVBs) via its interaction with the ESCRT-I complex (endosomal sorting complex required for transport I), and possibly also other ESCRT complexes. May act as a negative regulator of Ras-mediated mitogenic activity. Plays a role in ciliogenesis.[1] [2] [3] [STAM2_HUMAN] Involved in intracellular signal transduction mediated by cytokines and growth factors. Upon IL-2 and GM-CSL stimulation, it plays a role in signaling leading to DNA synthesis and MYC induction. May also play a role in T-cell development. Involved in down-regulation of receptor tyrosine kinase via multivesicular body (MVBs) when complexed with HGS (ESCRT-0 complex). The ESCRT-0 complex binds ubiquitin and acts as sorting machinery that recognizes ubiquitinated receptors and transfers them to further sequential lysosomal sorting/trafficking processes (By similarity). Publication Abstract from PubMedEGFR is a key player in cell proliferation and survival signaling, and its sorting into MVBs for eventual lysosomal degradation is controlled by the coordination of multiple ESCRT complexes on the endosomal membrane. HD-PTP is a cytosolic protein tyrosine phosphatase, and is associated with EGFR trafficking by interacting with the ESCRT-0 protein STAM2 and the ESCRT-III protein CHMP4B via its N-terminal Bro1 domain. Intriguingly, the homologous domain of two other human Bro1 domain-containing proteins, Alix and Brox, binds CHMP4B but not STAM2, despite their high structural similarity. To elucidate this binding specificity, we determined the complex structure of the HD-PTP Bro1 domain bound to the STAM2 core region. STAM2 binds to the hydrophobic concave pocket of the HD-PTP Bro1 domain, as CHMP4B does to the pocket of Alix, Brox, or HD-PTP but in the opposite direction. Critically, Thr145 of HD-PTP, corresponding to Lys151 of Alix and Arg145 of Brox, is revealed to be a determinant residue enabling this protein to bind STAM2, as the Alix- or Brox-mimicking mutations of this residue blocks the intermolecular interaction. This work therefore provides the structural basis for how HD-PTP recognizes the ESCRT-0 component to control EGFR sorting. Structural Study of the HD-PTP Bro1 Domain in a Complex with the Core Region of STAM2, a Subunit of ESCRT-0.,Lee J, Oh KJ, Lee D, Kim BY, Choi JS, Ku B, Kim SJ PLoS One. 2016 Feb 11;11(2):e0149113. doi: 10.1371/journal.pone.0149113., eCollection 2016. PMID:26866605[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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