Gap Channels

Gap channels (gap junctions) are specialized cell-cell contacts that provide direct intracellular communication. They allow passive diffusion of molecules up to 1 kDa, including nutrients, metabolites (glucose), ions (K+, Ca2+) and second messengers (IP3, cAMP).

Gene Data

Gap Channel Blockers

Cat. No. Product Name / Activity
3348 10Panx
Panx-1 mimetic inhibitory peptide; blocks pannexin-1 gap junctions
3096 Carbenoxolone disodium
Gap junction blocker. Also inhibitor of 11 β-hydroxysteroid dehydrogenase
1476 Gap 27
Selective gap junction blocker
5353 Gap19
Cx43 hemichannel blocker
6819 Mefloquine hydrochloride
Cx36 and Cx50 gap channel blocker; also antimalarial and antischistosomal
6227 TAT-Gap19
Cx43 hemichannel blocker
3863 Trovafloxacin mesylate
Inhibits Panx-1; Antibiotic


Cat. No. Product Name / Activity
7402 TAT-Gap19(I130A)
Control peptide for TAT-Gap19

Gap channels (also known as gap junctions) are specalized cell-cell contacts between almost all eukaryotic cells that provide direct intracellular communication. Generally, gap channels allow the passive diffusion of molecules up to 1 kDa which includes nutrients, small metabolites (e.g. glucose), ions (K+, Ca2+) and second messengers (IP3, cAMP and cGMP).

Gap channels allow electrical and biochemical coupling between cells and in excitable tissues, such as neurons and the heart, enables the generation of synchronized and rapid responses. Structurally, gap channels are composed of two hemichannels called 'connexons', which themselves are formed from six connexin molecules. Homo- and heteromeric combinations are seen, which exhibit distinct permeability, selectivity and functional properties.

Pannexins are related to connexins and can also form gap junctions. However, their expression is limited to the brain. Furthermore, in nonchordate animals a family of proteins called innexins form these channels.

Gap channels are regulated through post-translational modifications of the C'-terminal cytoplasmic tail and phosphorylation modulates assembly and their physiological properties. They are continuously synthesized and degraded, allowing tissues to rapidly adapt to changing environmental conditions.

Connexins play a key role in many physiological processes including cardiac and smooth muscle contraction, regulation of neuronal excitability, epithelial electrolyte transport and keratinocyte differentiation. Mutations in connexin genes are associated with human diseases including sensorineural deafness, a variety of skin disorders, peripheral neuropathy and cardiovascular disease.

External sources of pharmacological information for Gap Channels :

    Connexin and Pannexin Gene Data

    Gene Species Gene Symbol Gene Accession No. Protein Accession No.
    Gap Junction Protein α1
    (Connexin 43)
    Human GJA1 NM_000165 P17302
    Mouse Gja1 NM_010288 P23242
    Rat Gja1 NM_012567 P08050
    Gap Junction Protein α3
    (Connexin 46)
    Human GJA3 NM_021954 Q9Y6H8
    Mouse Gja3 NM_016975 Q64448
    Rat Gja3 NM_024376 P29414
    Gap Junction Protein α4
    (Connexin 37)
    Human GJA4 NM_002060 P35212
    Mouse Gja4 NM_008120 P28235
    Rat Gja4 NM_021654 Q03190
    Gap Junction Protein α5
    (Connexin 40)
    Human GJA5 NM_181703 P36382
    Mouse Gja5 NM_008121 Q01231
    Rat Gja5 NM_019280 P28234
    Gap Junction Protein α6
    (Connexin 33)
    Mouse Gja6 NM_001001496 Q6S5G4
    Rat Gja6 NM_019308 P28233
    Gap Junction Protein α7
    (Connexin 45)
    Rat Gja7 NM_001085381 Q8CJ21
    Gap Junction Protein α8
    (Connexin 50)
    Human GJA8 NM_005267 P48165
    Mouse Gja8 NM_008123 P28236
    Rat Gja8 NM_153465 Q8CJ20
    Gap Junction Protein α9
    (Connexin 59)
    Human GJA9 NM_030772 P57773
    Gap Junction Protein α10
    (Connexin 62)
    Human GJA10 NM_032602 Q969M2
    Mouse Gja10 NM_010289 Q9WUS4
    Rat Gja10 XM_232859 Q5I9W2
    Gap Junction Protein β1
    (Connexin 32)
    Human GJB1 NM_000166 P08034
    Mouse Gjb1 NM_008124 P28230
    Rat Gjb1 NM_017251 P08033
    Gap Junction Protein β2
    (Connexin 26)
    Human GJB2 NM_004004 Q96AK0
    Mouse Gjb2 NM_008125 Q00977
    Rat Gjb2 NM_001004099 P21994
    Gap Junction Protein β3
    (Connexin 31)
    Human GJB3 NM_024009 O75712
    Mouse Gjb3 NM_008126 P28231
    Rat Gjb3 NM_019240 P25305
    Gap Junction Protein β4
    (Connexin 30.3)
    Human GJB4 NM_153212 Q9NTQ9
    Mouse Gjb4 NM_008127 Q3V3R4
    Rat Gjb4 NM_053984 P36380
    Gap Junction Protein β5
    (Connexin 31.1)
    Human GJB5 NM_005268 O95377
    Mouse Gjb5 NM_010291 Q02739
    Rat Gjb5 NM_019241 P28232
    Gap Junction Protein β6
    (Connexin 30)
    Human GJB6 NM_006783 O95452
    Mouse Gjb6 NM_001010937 P70689
    Rat Gjb6 NM_053388 Q6AZ42
    Gap Junction Protein β7
    (Connexin 25)
    Human GJB7 NM_198568 Q6PEY0
    Gap Junction Protein γ1
    (Connexin 45)
    Human GJC1 NM_005497 P36383
    Mouse Gjc1 NM_008122 P28229
    Gap Junction Protein γ2
    (Connexin 47)
    Human GJC2 NM_020435 Q5T442
    Mouse Gjc2 NM_175452 Q8BQU6
    Rat Gjc2 XM_573100 Q80XF7
    Gap Junction Protein γ3
    (Connexin 30.2)
    Human GJC3 NM_181538 Q8NFK1
    Mouse Gjc3 NM_080450 Q921C1
    Rat Gjc3 XM_221997 Q80XF8
    Gap Junction Protein δ2
    (Connexin 36)
    Human GJD2 NM_020660 Q9UKL4
    Mouse Gjd2 NM_010290 O54851
    Rat Gjd2 NM_019281 O70610
    Gap Junction Protein δ3
    (Connexin 31.9)
    Human GJD3 NM_152219 Q8N144
    Mouse Gjd3 NM_178596 Q91YD1
    Rat Gjd3 XM_343965 Q5I203
    Gap Junction Protein δ4
    (Connexin 40.1)
    Human GJD4 NM_153368 Q96KN9
    Mouse Gjd4 NM_153086 Q8BSD4
    Rat Gjd4 XM_001068116 Q5I9W3
    Gap Junction Protein ε1
    (Connexin 23)
    Mouse Gje1 AK018698 Q9CX92
    Rat Gje1 XM_001060987 XP_001060987
    Pannexin 1 Human PANX1 NM_015368 Q96RD7
    Mouse Panx1 NM_019482 Q9JIP4
    Rat Panx1 NM_199397 P60570
    Pannexin 2 Human PANX2 NM_052839 Q96RD6
    Mouse Panx2 NM_001002005 Q6IMP4
    Rat Panx2 NM_199409 P60571
    Pannexin 3 Human PANX3 NM_052959 Q96QZ0
    Mouse Panx3 NM_172454 Q8CEG0
    Rat Panx3 NM_199398 P60572