HD-PTP and Alix share some membrane-traffic related proteins that interact with their Bro1 domains or proline-rich regions

VPS37 Isoforms Differentially Modulate the Ternary Complex Formation of ALIX, ALG-2, and ESCRT-I

“…Indeed, we have found that HD-PTP associates with TSG101 in a Ca 2þ -independent manner, suggesting that ALG-2 is dispensable as an adaptor. 12) Thus ESCRT-I complexes containing VPS37B or VPS37C, by having different affinities to ALG-2 than their isoform counterparts, might have different functional modulations than the ESCRT-I isocomplex A, for example. Future studies investigating the functional diversity of ESCRT-I isocomplexes must consider the possibility of modulation by Ca 2þ and ALG-2.…”

Myopic acts in the endocytic pathway to enhance signaling by theDrosophilaEGF receptor

“…HD-PTP shares with Alix the ability to bind Snf7 and Tsg101, but does not bind to Ruk (Ichioka et al, 2007). PTP-TD14 was found to suppress cell transformation by Ha-Ras, and required phosphatase activity for this function (Cao et al, 1998).…”

“…Mop acts upstream of Ras activation to promote the function of activated, internalized EGFR. Mop is homologous to human HD-PTP (PTPN23 -Human Gene Nomenclature Database) (Toyooka et al, 2000), which contains a Bro1 domain that is able to bind the ESCRT-III complex component SNF7 (CHMP4B -Human Gene Nomenclature Database) (Ichioka et al, 2007;Kim et al, 2005) and a tyrosine phosphatase domain. Mop is present on intracellular vesicles, and cells lacking mop have enlarged endosomes and reduced cleavage of the EGFR cytoplasmic domain.…”

Mammalian ESCRT-III-Related Protein IST1 Has a Distinctive Met-Pro Repeat Sequence That Is Essential for Interaction with ALG-2 in the Presence of Ca2+

“…The construction of GFP-fused mammalian expression vectors for wild-type (WT) human ALIX, ALIX PRR (717-868 aa), and ALIX 795{827 , Strep-tagged mammalian expression vectors for wild-type (WT) human ALIX and the deletion mutant of the ALG-2-binding site (Á795-841 aa, ALIX ÁABS ), and expression vectors for 3xFLAG-tagged CHMP6, CHMP1A and CHMP1B were described previously. 10,[16][17][18][19] Expression vectors of the IST1 isoform (full-364, containing four Met-Pro repeats) and deletion mutants (Nt and Ct) were obtained by PCR-cloning with KOD-Plus-Ver.2 DNA polymerase (Toyobo, Osaka) using specific primers (Supplemental Table S1) and pCMV-3xFLAG-IST1 as template. 20) Fragments were inserted between the EcoRI site and the SalI site of pEGFP-C3 with an InFusion Advantage PCR Cloning Kit (Clontech/Takara Bio, Otsu).…”

“…Previously, we found that an ALG-2 dimer functions as a Ca 2þ -dependent adaptor protein that bridges TSG101 and ALIX, which associate with each other weakly in the absence of Ca 2þ /ALG-2. 16,18) Since IST1 has been reported to interact with VPS37B, a component of ESCRT-I complex, 21) we performed Strep-pulldown assays using Strep-IST1 in the presence of Ca 2þ and of EGTA. No specific interaction between IST1 and ESCRT-I was observed (data not shown), suggesting that ALG-2 has no Ca 2þ -dependent adaptor function in bridging IST1 and ESCRT-I.…”