Transmembrane transport
Transmembrane transport spans solute carriers (SLCs), ATP-driven pumps, ion channels, aquaporins (AQPs), and ABC efflux proteins—governing nutrient uptake, ion homeostasis, pH/osmolarity, excitability, and drug disposition. Vesicular trafficking (endocytosis/secretion) with SNARE–RAB machinery sorts cargo and drives fusion between membrane compartments. Altered transporter expression or function links to cancer metabolism, MDR, neuropathology, and channelopathies.
1. Key targets
Core nodes
- SLC 家族
GLUT/SLC2 glucose carriers, amino-acid/oligopeptide transporters, MCT/SLC16 monocarboxylate carriers, xCT/SLC7A11 cystine–glutamate antiporter, and more.
- Pumps & exchangers
Na⁺/K⁺-ATPase sets electrochemical gradients; SERCA/PMCA shape cytosolic Ca²⁺; NCX/NKCC/NCC tune volume and pH.
- ABC 与囊泡机器
P-gp (ABCB1), BCRP, MRP-class efflux; SNAREs, RABs, and clathrin/caveolar routes for membrane dynamics.
Ion channels
- Voltage-gated Na⁺/K⁺/Ca²⁺ channels shape action potentials
- Ligand-gated and mechanosensitive channels tune sensation and secretion
Epithelia & barriers
- CFTR, ENaC, and tight junction proteins coordinate secretory vs absorptive polarity
- OATP/OAT/PEPT uptake transporters shape hepatic uptake and biliary excretion
Supplement: transmembrane transport targets (gene symbols)
Below the overview, HGNC symbols are grouped by SLC families (glucose, amino acids, neurotransmitters, peptide/MCT, organic ions, OATP, bicarbonate/pH, mitochondrial carriers, metals/vitamins), ABC efflux, P- and V-type ATPases, aquaporins, epithelial CFTR/ENaC/tight junctions, vesicular SNARE–RAB–clathrin, gap junctions, and representative ion-channel superfamilies. Channel gene sets are huge—voltage-gated and TRP/ligand-gated blocks are representative; use HGNC/IUPHAR for authoritative lists.
SLC: glucose & SLC5
SLC1 & SLC3–7 (amino acids & xCT)
SLC6 neurotransmitter transporters
SLC15 / 16 / 17 / 18 / 32
SLC22 & SLCO (OAT/OCT/OATP)
SLC4/8/9/10/12/20/34 (ions & pH)
SLC4 bicarbonate transport / Cl⁻–HCO₃⁻ exchange
SLC4A1, SLC4A2, SLC4A3, SLC4A4, SLC4A5, SLC4A7, SLC4A8, SLC4A9, SLC4A10, SLC4A11
Na⁺/Ca²⁺ exchangers, NHE, bile-acid transporters, cation–Cl⁻ cotransporters
SLC8A1, SLC8A2, SLC8A3, SLC9A1, SLC9A2, SLC9A3, SLC9A3R1, SLC9A3R2, SLC9A4, SLC9A5, SLC9A6, SLC9A7, SLC9A8, SLC9A9, SLC9A10, SLC9A11, SLC10A1, SLC10A2, SLC10A3, SLC10A4, SLC10A5, SLC10A6, SLC10A7, SLC12A1, SLC12A2, SLC12A3, SLC12A4, SLC12A5, SLC12A6, SLC12A7, SLC12A8, SLC12A9, SLC20A1, SLC20A2, SLC34A1, SLC34A2, SLC34A3
SLC25 mitochondrial carriers
SLC25 mitochondrial carrier family (selected)
Large SLC25 family; representative metabolic/nucleotide/cofactor carriers.
SLC25A1, SLC25A2, SLC25A3, SLC25A4, SLC25A5, SLC25A6, SLC25A10, SLC25A11, SLC25A12, SLC25A13, SLC25A14, SLC25A15, SLC25A16, SLC25A17, SLC25A18, SLC25A19, SLC25A20, SLC25A21, SLC25A22, SLC25A23, SLC25A24, SLC25A25, SLC25A26, SLC25A27, SLC25A28, SLC25A29, SLC25A30, SLC25A31, SLC25A32, SLC25A33, SLC25A34, SLC25A35, SLC25A36, SLC25A37, SLC25A38, SLC25A39, SLC25A40, SLC25A41, SLC25A42, SLC25A43, SLC25A44, SLC25A45, SLC25A46, SLC25A47, SLC25A48, SLC25A51, SLC25A52, SLC25A53
Metal, vitamin & nucleoside transport
Zinc, copper, iron transporters & related SLCs
SLC30A1, SLC30A2, SLC30A3, SLC30A4, SLC30A5, SLC30A6, SLC30A7, SLC30A8, SLC30A9, SLC30A10, SLC39A1, SLC39A2, SLC39A3, SLC39A4, SLC39A5, SLC39A6, SLC39A7, SLC39A8, SLC39A9, SLC39A10, SLC39A11, SLC39A12, SLC39A13, SLC39A14, SLC40A1, SLC11A1, SLC11A2, SLC31A1, SLC31A2
ABC
ABC transporter superfamily (major members)
ABCB1 is P-gp; ABCC includes MRP/CFTR; ABCG includes BCRP.
ABCA1, ABCA2, ABCA3, ABCA4, ABCA5, ABCA6, ABCA7, ABCA8, ABCA9, ABCA10, ABCA12, ABCA13, ABCB1, ABCB4, ABCB5, ABCB6, ABCB7, ABCB8, ABCB9, ABCB10, ABCB11, ABCC1, ABCC2, ABCC3, ABCC4, ABCC5, ABCC6, ABCC8, ABCC9, ABCC10, ABCC11, ABCC12, ABCD1, ABCD2, ABCD3, ABCD4, ABCE1, ABCF1, ABCF2, ABCF3, ABCG1, ABCG2, ABCG4, ABCG5, ABCG8
P-type & V-type ATPases
P-type ATPases (Na⁺/K⁺, Ca²⁺, H⁺/K⁺, Cu, etc.)
ATP1A1, ATP1A2, ATP1A3, ATP1A4, ATP1B1, ATP1B2, ATP1B3, ATP1B4, ATP2A1, ATP2A2, ATP2A3, ATP2B1, ATP2B2, ATP2B3, ATP2B4, ATP4A, ATP4B, ATP7A, ATP7B, ATP11A, ATP11B, ATP11C, ATP8A1, ATP8A2, ATP8B1, ATP8B2, ATP8B3, ATP8B4, ATP9A, ATP9B, ATP10A, ATP10B, ATP10D, ATP12A
Aquaporins (AQP)
CFTR, ENaC & tight junctions
Tight junctions & epithelial polarity (selected)
TJP1, TJP2, TJP3, CLDN1, CLDN2, CLDN3, CLDN4, CLDN5, CLDN6, CLDN7, CLDN8, CLDN9, CLDN10, CLDN11, CLDN12, CLDN14, CLDN15, CLDN16, CLDN17, CLDN18, CLDN19, CLDN20, CLDN22, CLDN23, CLDN24, OCLN, MARVELD2, MARVELD3, CGN, CGNL1, PARD3, PARD6A, PARD6B, PARD6G
SNAREs, RABs & clathrin
SNARE & membrane fusion machinery (selected)
STX1A, STX1B, STX2, STX3, STX4, STX5, STX6, STX7, STX8, STX11, STX12, STX16, STX17, STX18, STX19, SNAP25, SNAP29, SNAP47, SNAPIN, VAMP1, VAMP2, VAMP3, VAMP4, VAMP5, VAMP7, VAMP8, YKT6, STXBP1, STXBP2, STXBP3, STXBP4, STXBP5, STXBP6, NSF, NAPA, NAPB
RAB GTPases & clathrin/adaptor proteins (selected)
RAB1A, RAB1B, RAB2A, RAB2B, RAB3A, RAB3B, RAB3C, RAB3D, RAB4A, RAB4B, RAB5A, RAB5B, RAB5C, RAB6A, RAB6B, RAB7A, RAB7B, RAB8A, RAB8B, RAB9A, RAB9B, RAB10, RAB11A, RAB11B, RAB12, RAB13, RAB14, RAB15, RAB17, RAB18, RAB19, RAB20, RAB21, RAB22A, RAB22B, RAB23, RAB24, RAB25, RAB26, RAB27A, RAB27B, RAB28, RAB29, RAB30, RAB31, RAB32, RAB33A, RAB33B, RAB34, RAB35, RAB36, RAB37, RAB38, RAB39A, RAB39B, RAB40A, RAB40B, RAB41, RAB42, RAB43, CLTC, CLTB, CLTCL1, AP2A1, AP2A2, AP2B1, AP2M1, AP2S1, AP1A1, AP1A2, AP1B1, AP1G1, AP1G2, AP1M1, AP1M2, AP1S1, AP1S2, AP1S3
Gap junctions & pannexins
Ion channels (representative genes)
Voltage-gated Na⁺/K⁺/Ca²⁺ channels (representative genes)
Very large gene families; representative disease/drug-target–linked genes.
SCN1A, SCN2A, SCN3A, SCN4A, SCN5A, SCN7A, SCN8A, SCN9A, SCN10A, SCN11A, SCN1B, SCN2B, SCN3B, SCN4B, KCNQ1, KCNQ2, KCNQ3, KCNQ4, KCNQ5, KCNH2, KCNA1, KCNA2, KCNA3, KCNA4, KCNA5, KCNA6, KCNA7, KCNA10, CACNA1A, CACNA1B, CACNA1C, CACNA1D, CACNA1E, CACNA1F, CACNA1G, CACNA1H, CACNA1I, CACNA1S, CACNA2D1, CACNA2D2, CACNA2D3, CACNA2D4, CACNB1, CACNB2, CACNB3, CACNB4, CACNG1, CACNG2, CACNG3, CACNG4, CACNG5, CACNG6, CACNG7, CACNG8
TRP, mechanosensitive & ligand-gated channels (representative)
TRPA1, TRPC1, TRPC3, TRPC4, TRPC5, TRPC6, TRPC7, TRPM1, TRPM2, TRPM3, TRPM4, TRPM5, TRPM6, TRPM7, TRPM8, TRPV1, TRPV2, TRPV3, TRPV4, TRPV5, TRPV6, TRPML1, TRPML2, TRPML3, PKD1, PKD2, PKD1L1, PKD1L2, PKD2L1, PKD2L2, PIEZO1, PIEZO2, CHRNA1, CHRNA2, CHRNA3, CHRNA4, CHRNA5, CHRNA6, CHRNA7, CHRNA9, CHRNA10, CHRNB1, CHRNB2, CHRNB3, CHRNB4, CHRND, CHRNE, CHRNG, GRIA1, GRIA2, GRIA3, GRIA4, GRIN1, GRIN2A, GRIN2B, GRIN2C, GRIN2D, GRIN3A, GRIN3B, GRIK1, GRIK2, GRIK3, GRIK4, GRIK5, GRID1, GRID2
2. Suggested experimental readouts
Separate surface expression, subcellular localization, and functional activity; pair pharmacological probes with genetic knockdown/knockout.
- Surface biotinylation / flow cytometry for membrane abundance
- Radiolabeled or fluorescent substrate uptake (Vmax/Km; note vectorial transport)
- Patch clamp / Ca² imaging for channel electrophysiology
- pHi indicators (NHE / bicarbonate-coupled transport)
- RAB7/LAMP1 cargo colocalization (endolysosomal flux)
3. Transport modes (summary)
| Class | Energy / driving force | Examples |
|---|---|---|
| Facilitated diffusion | Down electrochemical gradient; no direct ATP hydrolysis | GLUT、部分 AQP、电压非依赖性载体 |
| Secondary active | Coupled to ion gradients (often established by Na⁺/K⁺-ATPase) | SGLT、神经递质转运体、部分氨基酸转运体 |
| Primary active | ATP 水解 | Na⁺/K⁺-ATPase、SERCA、ABC 外排泵 |
4. PK, resistance & disease context
- DDI 与肝脏摄取: hepatic uptake transporters (e.g., OATP1B1/1B3, OCTs) are key DDI nodes for precision dosing.
- 肿瘤耐药: ABCB1/ABCG2/ABCC overexpression limits intracellular drug accumulation—cross-talk with metabolism/autophagy.
- Channelopathies: mutations in Na⁺/K⁺/Ca²⁺ channels cause arrhythmia, epilepsy, and neuromuscular disorders.
Transmembrane transport–related antibodies (curated)
5. Product lines & on-site search
Primary & phospho antibodies
GLUT1/4, MCT1/4, xCT, P-gp, BCRP, OATPs, Na⁺/K⁺-ATPase, SERCA, NCX, NKCC, CFTR, AQPs, voltage-gated channels, SNARE/RAB—WB/IHC/IF/FC per clone/species.
6. Inhibitors & tool compounds (summary)
For research use; mind species differences, off-targets, and concentration dependence—follow datasheets and ethics.
Classical Na⁺/K⁺-ATPase inhibitor (cytotoxic at high doses).
P-gp (ABCB1) modulation tools; common in DDI studies.
Loop diuretics; NKCC-related targets (model-dependent).
OAT-class inhibitor probe (off-target caution).
ENaC-related research tool.
V-ATPase inhibitor; endolysosomal acidification studies.
7. Pathway schematic
- SLCs mediate facilitated or coupled transport
- ATPases establish and maintain gradients
- Ion channels and aquaporins enable rapid flux
- ABC efflux and vesicular machinery shape disposition and membrane dynamics
8. Pathway biology overview
Transport networks couple tightly to metabolism, signaling, and cytoskeleton—for example, glucose uptake constrains glycolytic programs; cystine import supports glutathione redox homeostasis. In drug discovery, transporters are both targets and determinants of tissue distribution and clearance.
- Polarized epithelia segregate apical vs basolateral transporters to set vectorial transport
- Endocytosis–recycling balances surface abundance of receptors and transporters
9. Related pathways on this site
10. External databases & modification resources
- KEGG: hsa02010 ABC transporters
- PharmGKB (transporter/channel pharmacogenomics)
- Reactome: Transport of small molecules (R-HSA-382551)
- WikiPathways (search: transmembrane transport)
- PhosphoSitePlus (regulatory PTMs on transporters/channels)
11. References
SLC / ABC
- • Hediger MA, et al. (2004). Pflugers Arch. 447(5):465-76.
- • Gottesman MM, et al. (2002). Nat Rev Cancer. 2(1):48-58.
Vesicles & membrane traffic
- • Südhof TC, Rothman JE. (2009). Science. 323(5913):474-7.