What is TRPML
TRPML is a family of transient receptor potential ion channels.
The three members of the TRPML sub-family are not well characterized. TRPML1 is known to be localized in late endosomes. This subunit also contains a lipase domain between its S1 and S2 segments. While the function of this domain is unknown it has been proposed that it is involved in channel regulation. Physiological studies have described TRPML1 channels as proton leak channels in lysosomes responsible for preventing these organelles from becoming too acidic. TRPML2 and TRPML3 have yet to be characterized.[1]
Deficiencies can lead to enlarged vacuoles.
Tags: Integral membrane proteins, Ion channels, Membrane proteins, Proteins, Transmembrane proteins
This entry was posted
on Thursday, December 25th, 2008 at 12:39 am and is filed under Nutrients.
You can follow any responses to this entry through the RSS 2.0 feed.
You can leave a response, or trackback from your own site.
There are other types of ion channel classifications that are based on less normal characteristics, e.g. multiple pores and transient potentials.
Almost all ion channels have one single pore. However, there are also those with two:
Two-pore channels: This small family of 2 members putatively forms cation-selective ion channels. They are predicted to contain two KV-style six-transmembrane domains, suggesting they form a dimer in the membrane. These channels are related to catsper channels channels and, more distantly, TRP channels.
There are channels that are classified by the duration of the response to stimuli:
Transient receptor potential channels: This group of channels, normally referred to
Voltage-gated channels open and close in response to membrane potential.
Voltage-gated sodium channels: This family contains at least 9 members and is largely responsible for action potential creation and propagation. The pore-forming ? subunits are very large (up to 4,000 amino acids) and consist of four homologous repeat domains (I-IV) each comprising six transmembrane segments (S1-S6) for a total of 24 transmembrane segments. The members of this family also coassemble with auxiliary ? subunits, each spanning the membrane once. Both ? and ? subunits are extensively glycosylated.
Voltage-gated calcium channels: This family contains 10 members, though these members are known to coassemble