Table 1 Proteins and protein complexes involved in the regulation of transcellular transport in ECs.

PLVAP

Plasmalemma vesicle-associated protein

Forms a molecular-sieve structure, also known as stomatal and fenestral diaphragms, on top of caveolae, fenestrae and transendothelial channels

Regulates caveolar shape

^{25, 26, 31, 32}

CAV1

Caveolin-1

Structural component of caveolae

Regulates caveolae biogenesis

³³

CLTC

Clathrin

Clathrin heavy chain and light chain assemble in a trimeric structure called triskelion, that constitutes the clathrin coat

Clathrin-coated vesicles play a role in receptor-mediated uptake of molecules

^{34, 35}

DNM1 or DNM2

Dynamin-1 or dynamin-2

Regulates membrane fission, necessary for endocytosis

³⁶

FLOT1 or FLOT2

Flotillin-1 or flotillin-2

Are enriched in lipid rafts

May induce membrane invaginations, reminiscent of caveolae

May stabilize caveolin-1 levels by preventing lysosomal degradation

^{37, 38}

MFSD2A

Major facilitator superfamily domain containing 2a

Lipid transporter that alters the lipid composition of the luminal plasma membrane of CNS ECs, thereby preventing caveolae formation and caveolae-mediated transcytosis

^{39, 40}

NSF

N-ethylmaleimide sensitive fusion

Regulates disassembly of SNARE complexes and their recycling

⁴¹

SNAP23

Synaptosomal-associated protein 23

Component of the endothelial SNARE machinery

Regulates endothelial exocytosis

^{42, 43}

PACSIN2

Protein kinase C and casein kinase substrate in neurons 2

F-BAR domain protein that regulates membrane sculpting of caveolae

Stabilizes caveolae at the membrane

^{44, 45}

VAMP2, VAMP3 or VAMP8

Vesicle-associated membrane protein-2, -3 or -8

SNARE complex protein present on vesicles

Mediates fusion of vesicles with target membrane

^{46, 47}