SH3 domain and tetratricopeptide repeats-containing protein 2 is a
protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residue (biochemistry), residues. Proteins perform a vast array of functions within organisms, including Enzyme catalysis, catalysing metab ...
that in humans is encoded by the ''SH3TC2''
gene
In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protei ...
.
It is believed to be expressed in the
Schwann cell
Schwann cells or neurolemmocytes (named after German physiologist Theodor Schwann) are the principal glia of the peripheral nervous system (PNS). Glial cells function to support neurons and in the PNS, also include Satellite glial cell, satellite ...
s that wrap the
myelin
Myelin Sheath ( ) is a lipid-rich material that in most vertebrates surrounds the axons of neurons to insulate them and increase the rate at which electrical impulses (called action potentials) pass along the axon. The myelinated axon can be lik ...
sheath around nerves.
Function
This gene encodes a protein with two
N-terminal
The N-terminus (also known as the amino-terminus, NH2-terminus, N-terminal end or amine-terminus) is the start of a protein or polypeptide, referring to the free amine group (-NH2) located at the end of a polypeptide. Within a peptide, the amin ...
Src homology 3 (
SH3) domains and 10 tetratricopeptide repeat (
TPR) motifs, and is a member of a small gene family. The gene product has been proposed to be an
adapter
An adapter or adaptor is a device that converts attributes of one electrical device or system to those of an otherwise incompatible device or system. Some modify power or signal attributes, while others merely adapt the physical form of one co ...
or docking molecule.
The mouse version (orthologue) of SH3TC2 is believed to be expressed in Schwann cells. The tagged protein localizes to the plasma membrane and to the
perinuclear endocytic recycling compartment. Mice lacking Sh3tc2 have an abnormal organization of the
node of Ranvier
Nodes of Ranvier ( ), also known as myelin-sheath gaps, occur along a myelinated axon where the axolemma is exposed to the extracellular space. Nodes of Ranvier are uninsulated axonal domains that are high in sodium and potassium ion channels co ...
consistent with the idea that the protein might have a role in myelination or in
axon
An axon (from Greek ἄξων ''áxōn'', axis) or nerve fiber (or nerve fibre: see American and British English spelling differences#-re, -er, spelling differences) is a long, slender cellular extensions, projection of a nerve cell, or neuron, ...
–
glial cell
Glia, also called glial cells (gliocytes) or neuroglia, are non-neuronal cells in the central nervous system (the brain and the spinal cord) and in the peripheral nervous system that do not produce electrical impulses. The neuroglia make up ...
interactions.
Clinical significance
Mutations in SH3TC2 are known to cause the following conditions:
*
Charcot-Marie-Tooth disease type 4C, an autosomal recessive childhood-onset neurodegenerative disease characterized by demyelination of motor and sensory neurons;
* Mononeuropathy of the median nerve (MNMN) at the wrist.
References
Further reading
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External links
GeneReviews/NCBI/NIH/UW entry on Charcot-Marie-Tooth Neuropathy Type 4 GeneReviews/NCBI/NIH/UW entry on Charcot-Marie-Tooth Neuropathy Type 4C
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