Table 1.
Proteins targeted and antibodies used in this study
| Target proteina | Major/minor localization and function of the target protein | Nature of antibody (source)b | Reference(s)c |
|---|---|---|---|
| Markers of major secretory organelles | |||
| Heat shock 70-kDa protein 5 (HSPA5) (immunoglobulin heavy chain-binding protein [Bip]; 78-kDa glucose-regulated protein [GRP78]; MIF2; FLJ26106) | ER lumen (major); nucleus and cell surface (minor). Molecular chaperone that controls the structural maturation of nascent glycoproteins. Detects hydrophobic patches on improperly folded proteins and initiates the unfolded protein response, thereby serving as an ER stress sensor. | Rabbit polyclonal antibody (Abcam catalog no. ab21685) | 21, 43, 47 |
| Golgin subfamily A member 2 (GOLGA2) (130-kDa cis-Golgi matrix protein I [GM130]; SY11 protein; Golgi autoantigen; Golgin-95; RP11-395P17.5; MGC20672) | cis-Golgi matrix peripheral membrane protein. Functions as a structural element and provides attachment sites for other membranes and proteins of the Golgi apparatus. | MAb, clone 35/GM130 (BD catalog no. 610822) | 3 |
| Mannosidase, alpha, class 2A, member 1 (MAN2A1) (alpha-mannosidase 2 [AMan II]; Golgi alpha-mannosidase II [MANA2]; Golgi integral membrane protein 7 [GOLIM7]; mannosidase, alpha type II [Mann II]; mannosyl-oligosaccharide 1,3-1,6-alpha-mannosidase) | cis- and medial-Golgi. Golgi-matrix-interacting enzyme. Mediates interaction of cis- and medial-Golgi compartments. | Rabbit polyclonal antibody (Abcam catalog no. ab12277) | 45, 56 |
| Golgin subfamily A member 4 (Golgin A4) (OTTHUMP00000208897; OTTHUMP00000209805; Golgi autoantigen; Golgin subfamily a, 4; Golgin-240; Golgin-245; protein 72.1; trans-Golgi p230) | TGN GRIP domain protein. Important for biogenesis of distinct populations of vesicles that function in vesicular transport. | MAb, clone 15/p230 trans-Golgi (BD catalog no. 611280) | 20, 59 |
| Early endosome antigen 1 (EEA1) (endosome-associated protein p162; zinc finger FYVE domain-containing protein 2; MST105; MSTP105; ZFYVE2) | Early endosomes. Colocalizes in many cells with Rab5 and phosphatidylinositol 3-phosphate in the early endosomal compartment. Mediates endosome docking and, together with SNARE proteins, initiates membrane fusion. | MAb, clone 14/EEA1 (BD catalog no. 610456); rabbit polyclonal antibody (Abcam catalog no. ab2900) | 13, 28 |
| Markers of late endosomes | |||
| CD63 (melanoma 1 antigen; granulophysin; lysosome-associated membrane glycoprotein 3 [LAMP-3]; melanoma-associated antigen ME491; melanoma-associated antigen MLA1; ocular melanoma-associated antigen [OMA81H]; tetraspanin-30 [tspan-30]) | MVBs and other vesicles. Tetraspanin membrane protein abundant in multivesicular bodies. Cycles between these compartments and the exocytic pathway. | MAb, clone 4X-49.129.5 (SCBT catalog no. 5275) | 32, 46, 58 |
| Lysosome-associated membrane protein 1 (LAMP1) (CD107 antigen-like family member A [CD107a]; lysosome-associated membrane glycoprotein 1; LAMP1A; LGP120) | Lysosomes. Lysosome-associated glycosylated type I membrane protein. | MAb, clone H5G11 (SCBT catalog no. sc-18821) | 10, 35 |
| Markers of recycling endosomes | |||
| Transferrin receptor (TFRC) (TR; p90; TRFR; transferrin receptor protein 1; CD71; TFR; TFR1; OTTHUMP00000208525; T9) | Recycling and sorting endosomes. Recycles between the cell surface and cytoplasmic vesicles, including lysosomes via late endosomes. | MAb, clone b3/25 (SCBT catalog no. sc-65877) | 12, 37 |
| RAB11A, member RAS oncogene family (RAB11A) (RAB11A, member oncogene family; Rab11; MGC1490; YL8) | Recycling endosomes. Located in the cytoplasmic space in the vicinity of several post-Golgi structures, including the TGN and recycling endosomes. Regulates distinct events in the transferrin receptor pathway. Not uniquely associated with any one organelle. | Rabbit polyclonal antibody, clone H-87 (SCBT catalog no. 9020) | 34, 39 |
| Markers for ESCRT III-associated proteins | |||
| Chromatin-modifying protein 1A (CHMP1A) (charged multivesicular body protein 1; charged multivesicular body protein 1a; hVps46-1; procollagen (type III) N-endopeptidase; protease, metallo 1, 33 kD; vacuolar protein sorting-associated protein 46-1; Vps46A; Vps46-1; KIAA0047; PCOLN3; PRSM1) | Required for sorting endosomal vesicles into MVBs and has role in budding of some viruses. Recruits Vps4 and the microtubule-severing enzyme spastin (mammalian DID2B) as part of regulating membrane scission and ESCRT III disassembly. | Rabbit polyclonal antibody, clone FL-196 (SCBT catalog no. 67205) | 25, 26 |
| Vacuolar protein sorting 4 homolog A (vacuolar sorting protein 4 [VPS4]; hVPS4; vacuolar protein sorting factor 4A; vacuolar protein sorting-associated protein 4A; FLJ22197; SKD1 homolog; SKD; SKD1A; SKD2; VPS4-1) | Involved in late endosomal protein transport. Plays role in MVB biogenesis, autophagy, and viral budding. Regulates ESCRT III disassembly. | Rabbit polyclonal antibody, clone H-165 (SCBT catalog no. 32922) | 26, 51 |
a
Official gene symbols and names. Prior and informal designations are shown in parentheses. Designations used in this paper are shown in bold.
b
Antibody sources are abbreviated as follows: Abcam, Abcam (Cambridge, MA); BD, BD Biosciences (San Jose, CA); SCBT, Santa Cruz Biotechnologies (Santa Cruz, CA).
c
References are for papers that describe or summarize functional and localization information for the markers, not necessarily primary citations for the antibody.