pH-Sensitive TRP Channel Antibody Explorer Kit

Transient receptor potential (TRP) channels consist of 6 transmembrane domains with a pore domain between transmembrane domains 5 and 6 and with both the C- and N-termini located intracellularly. There are five members of this family which are sensitive to pH changes.

The conductance of protons through TRPV1 results in intracellular acidification, which in turn acts on other membrane channels that are sensitive to changes in intracellular pH.  TRPV1 allows a sustained inward proton current only if the extracellular pH is below 6. When sensing acidotic conditions the temperature threshold for channel activation is lowered thus enabling it to function under normal body temperature.

Similar to TRPV1, TRPV4 opens when extracellular pH drops below 6 and the channel reaches its maximum current at a pH of about 4. TRPV4 is activated by citrate but not lactate and plays a role in mechano and osmosensation.

TRPC4 and TRPC5 channels form Ca²⁺ permeable cation channels that are involved in receptor-mediated increases in intracellular Ca²⁺. They respond to small pH decreases (7.4 to 7.0) by increasing both G protein-activated and channel spontaneous currents. Currents increase when the pH decreases to about 6.5 but are inhibited when pH is decreased further.

TRPP2 (also known as PKD2L1) is currently acknowledged as a pH-sensing channel after it has been discovered as having a major role in sour taste sensing. In order to form functional channels, PKD2L1 needs to associate as a heteromer with other proteins of the PKD1 family¹.