scholarly journals Protein Networks Supporting AP-3 Function in Targeting Lysosomal Membrane Proteins

2008 ◽  
Vol 19 (5) ◽  
pp. 1942-1951 ◽  
Author(s):  
Thorsten Baust ◽  
Mihaela Anitei ◽  
Cornelia Czupalla ◽  
Iryna Parshyna ◽  
Line Bourel ◽  
...  
Keyword(s):  
Membrane Proteins ◽  
Brefeldin A ◽  
Lysosomal Membrane ◽  
Exchange Factor ◽  
Proteomic Screen ◽  
Early Endosomes ◽  
Lysosomal Membrane Proteins ◽  
Guanosine Triphosphatase ◽  
Phosphatidylinositol 3

The AP-3 adaptor complex targets selected transmembrane proteins to lysosomes and lysosome-related organelles. We reconstituted its preferred interaction with liposomes containing the ADP ribosylation factor (ARF)-1 guanosine triphosphatase (GTPase), specific cargo tails, and phosphatidylinositol-3 phosphate, and then we performed a proteomic screen to identify new proteins supporting its sorting function. We identified ≈30 proteins belonging to three networks regulating either AP-3 coat assembly or septin polymerization or Rab7-dependent lysosomal transport. RNA interference shows that, among these proteins, the ARF-1 exchange factor brefeldin A-inhibited exchange factor 1, the ARF-1 GTPase-activating protein 1, the Cdc42-interacting Cdc42 effector protein 4, an effector of septin-polymerizing GTPases, and the phosphatidylinositol-3 kinase IIIC3 are key components regulating the targeting of lysosomal membrane proteins to lysosomes in vivo. This analysis reveals that these proteins, together with AP-3, play an essential role in protein sorting at early endosomes, thereby regulating the integrity of these organelles.

Lysosomal membrane proteins exposed to melanin in melanocyte B16F10

2016 ◽  
Vol 8 (3) ◽  
pp. 253-257
Author(s):  
Seung Hyuck Bang ◽  
Dong Jun Park ◽  
Yang-Hoon Kim ◽  
Jiho Min
Keyword(s):  
Membrane Proteins ◽  
Lysosomal Membrane ◽  
Lysosomal Membrane Proteins

scholarly journals NCU-G1 is a highly glycosylated integral membrane protein of the lysosome

2009 ◽  
Vol 422 (1) ◽  
pp. 83-90 ◽  
Author(s):  
Oliver Schieweck ◽  
Markus Damme ◽  
Bernd Schröder ◽  
Andrej Hasilik ◽  
Bernhard Schmidt ◽  
...  
Keyword(s):  
Amino Acid ◽  
Membrane Proteins ◽  
Membrane Protein ◽  
Mouse Liver ◽  
Lysosomal Membrane ◽  
Molecular Forms ◽  
Type I ◽  
Calculated Molecular Mass ◽  
Sorting Motif ◽  
Lysosomal Membrane Proteins

Until recently, a modest number of approx. 40 lysosomal membrane proteins had been identified and even fewer were characterized in their function. In a proteomic study, using lysosomal membranes from human placenta we identified several candidate lysosomal membrane proteins and proved the lysosomal localization of two of them. In the present study, we demonstrate the lysosomal localization of the mouse orthologue of the human C1orf85 protein, which has been termed kidney-predominant protein NCU-G1 (GenBank® accession number: AB027141). NCU-G1 encodes a 404 amino acid protein with a calculated molecular mass of 39 kDa. The bioinformatics analysis of its amino acid sequence suggests it is a type I transmembrane protein containing a single tyrosine-based consensus lysosomal sorting motif at position 400 within the 12-residue C-terminal tail. Its lysosomal localization was confirmed using immunofluorescence with a C-terminally His-tagged NCU-G1 and the lysosomal marker LAMP-1 (lysosome-associated membrane protein-1) as a reference, and by subcellular fractionation of mouse liver after a tyloxapol-induced density shift of the lysosomal fraction using an anti-NCU-G1 antiserum. In transiently transfected HT1080 and HeLa cells, the His-tagged NCU-G1 was detected in two molecular forms with apparent protein sizes of 70 and 80 kDa, and in mouse liver the endogenous wild-type NCU-G1 was detected as a 75 kDa protein. The remarkable difference between the apparent and the calculated molecular masses of NCU-G1 was shown, by digesting the protein with N-glycosidase F, to be due to an extensive glycosylation. The lysosomal localization was impaired by mutational replacement of an alanine residue for the tyrosine residue within the putative sorting motif.

The Response of Liposomes Modified with Lysosomal Membrane Proteins to the Targeting Ability Associated with Antimicrobial Activity

2018 ◽  
Vol 14 (12) ◽  
pp. 2198-2207
Author(s):  
Seung Hyuck Bang ◽  
Ra-Mi Park ◽  
Simranjeet Singh Sekhon ◽  
Geun Woo Lee ◽  
Yang-Hoon Kim ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Membrane Proteins ◽  
Lysosomal Membrane ◽  
Lysosomal Membrane Proteins ◽  
Targeting Ability

scholarly journals Glycolipid-Dependent Sorting of Melanosomal from Lysosomal Membrane Proteins by Lumenal Determinants

Traffic ◽  
2008 ◽  
Vol 9 (6) ◽  
pp. 951-963 ◽  
Author(s):  
Sophie Groux-Degroote ◽  
Suzanne M. van Dijk ◽  
Jasja Wolthoorn ◽  
Sylvia Neumann ◽  
Alexander C. Theos ◽  
...  
Keyword(s):  
Membrane Proteins ◽  
Lysosomal Membrane ◽  
Lysosomal Membrane Proteins

scholarly journals Brefeldin A-dependent Membrane Tubule Formation Reconstituted In Vitro Is Driven by a Cell Cycle–regulated Microtubule Motor

2000 ◽  
Vol 11 (3) ◽  
pp. 941-955 ◽  
Author(s):  
Alasdair M. Robertson ◽  
Victoria J. Allan
Keyword(s):  
Cell Cycle ◽  
Cultured Cells ◽  
Brefeldin A ◽  
Binding Activity ◽  
Membrane Dynamics ◽  
Dependent Manner ◽  
Tubule Formation ◽  
Early Endosomes

Treatment of cultured cells with brefeldin A (BFA) induces the formation of extensive membrane tubules from the Golgi apparatus,trans-Golgi network, and early endosomes in a microtubule-dependent manner. We have reconstituted this transport process in vitro using Xenopus egg cytosol and a rat liver Golgi-enriched membrane fraction. The presence of BFA results in the formation of an intricate, interconnected tubular membrane network, a process that, as in vivo, is inhibited by nocodazole, the H1 anti-kinesin monoclonal antibody, and by membrane pretreatment with guanosine 5′-O-(3-thiotriphosphate). Surprisingly, membrane tubule formation is not due to the action of conventional kinesin or any of the other motors implicated in Golgi membrane dynamics. Two candidate motors of ∼100 and ∼130 kDa have been identified using the H1 antibody, both of which exhibit motor properties in a biochemical assay. Finally, BFA-induced membrane tubule formation does not occur in metaphase cytosol, and because membrane binding of both candidate motors is not altered after incubation in metaphase compared with interphase cytosol, these results suggest that either the ATPase or microtubule-binding activity of the relevant motor is cell cycle regulated.

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