Protein: Periaxin (Q9BXM0)
Organism: Homo sapiens (Human)
Function: Scaffolding protein that functions as part of a dystroglycan complex in Schwann cells, and as part of EZR and AHNAK-containing complexes in eye lens fiber cells. Required for the maintenance of the peripheral myelin sheath that is essential for normal transmission of nerve impulses and normal perception of sensory stimuli. Required for normal transport of MBP mRNA from the perinuclear to the paranodal regions. Required for normal remyelination after nerve injury. Required for normal elongation of Schwann cells and normal length of the internodes between the nodes of Ranvier. The demyelinated nodes of Ranvier permit saltatory transmission of nerve impulses; shorter internodes cause slower transmission of nerve impulses. Required for the formation of appositions between the abaxonal surface of the myelin sheath and the Schwann cell plasma membrane; the Schwann cell cytoplasm is restricted to regions between these appositions. Required for the formation of Cajal bands and of Schmidt-Lanterman incisures that correspond to short, cytoplasm-filled regions on myelinated nerves. Recruits DRP2 to the Schwann cell plasma membrane. Required for normal protein composition of the eye lens fiber cell plasma membrane and normal eye lens fiber cell morphology.
Subcellular location: [Isoform 1]: Cell membrane {ECO:0000250|UniProtKB:O55103}; Peripheral membrane protein {ECO:0000250|UniProtKB:O55103}; Cytoplasmic side {ECO:0000250|UniProtKB:O55103}. Nucleus {ECO:0000269|PubMed:24633211}. Cytoplasm {ECO:0000269|PubMed:24633211}. Note=Detected in the Schwann cell nucleus prior to the onset of myelination. Detected in Schwann cells at periaxonal myelin membranes. Associated with the cell membrane during myelination. {ECO:0000250|UniProtKB:O55103}.; SUBCELLULAR LOCATION: [Isoform 2]: Cytoplasm {ECO:0000250|UniProtKB:O55103}.; SUBCELLULAR LOCATION: Cell membrane {ECO:0000250|UniProtKB:O55103}. Cell junction {ECO:0000250|UniProtKB:O55103}. Note=Colocalizes with ACTB at tricellular junctions between eye lens fiber cells. {ECO:0000250|UniProtKB:O55103}.
Interaction partners:
- Dystrophin-related protein 2
- Periplakin
- E3 SUMO-protein ligase EGR2
- Ezrin
- Neuroblast differentiation-associated protein AHNAK
- Transcription factor SOX-10
- Gap junction beta-1 protein
- Myelin P2 protein
- Myelin protein zero-like protein 1
- Utrophin
Sequence:
MEARSRSAEELRRAELVEIIVETEAQTGVSGINVAGGGKEGIFVRELREDSPAARSLSLQEGDQLLSARVFFENFKYEDALRLLQCAEPYKVSFCLKRTVPTGDLALRPGTVSGYEIKGPRAKVAKLNIQSLSPVKKKKMVPGALGVPADLAPVDVEFSFPKFSRLRRGLKAEAVKGPVPAAPARRRLQLPRLRVREVAEEAQAARLAAAAPPPRKAKVEAEVAAGARFTAPQVELVGPRLPGAEVGVPQVSAPKAAPSAEAAGGFALHLPTLGLGAPAPPAVEAPAVGIQVPQVELPALPSLPTLPTLPCLETREGAVSVVVPTLDVAAPTVGVDLALPGAEVEARGEAPEVALKMPRLSFPRFGARAKEVAEAKVAKVSPEARVKGPRLRMPTFGLSLLEPRPAAPEVVESKLKLPTIKMPSLGIGVSGPEVKVPKGPEVKLPKAPEVKLPKVPEAALPEVRLPEVELPKVSEMKLPKVPEMAVPEVRLPEVELPKVSEMKLPKVPEMAVPEVRLPEVQLLKVSEMKLPKVPEMAVPEVRLPEVQLPKVSEMKLPEVSEVAVPEVRLPEVQLPKVPEMKVPEMKLPKVPEMKLPEMKLPEVQLPKVPEMAVPDVHLPEVQLPKVPEMKLPEMKLPEVKLPKVPEMAVPDVHLPEVQLPKVPEMKLPKMPEMAVPEVRLPEVQLPKVSEMKLPKVPEMAVPDVHLPEVQLPKVCEMKVPDMKLPEIKLPKVPEMAVPDVHLPEVQLPKVSEIRLPEMQVPKVPDVHLPKAPEVKLPRAPEVQLKATKAEQAEGMEFGFKMPKMTMPKLGRAESPSRGKPGEAGAEVSGKLVTLPCLQPEVDGEAHVGVPSLTLPSVELDLPGALGLQGQVPAAKMGKGERVEGPEVAAGVREVGFRVPSVEIVTPQLPAVEIEEGRLEMIETKVKPSSKFSLPKFGLSGPKVAKAEAEGAGRATKLKVSKFAISLPKARVGAEAEAKGAGEAGLLPALDLSIPQLSLDAHLPSGKVEVAGADLKFKGPRFALPKFGVRGRDTEAAELVPGVAELEGKGWGWDGRVKMPKLKMPSFGLARGKEAEVQGDRASPGEKAESTAVQLKIPEVELVTLGAQEEGRAEGAVAVSGMQLSGLKVSTAGQVVTEGHDAGLRMPPLGISLPQVELTGFGEAGTPGQQAQSTVPSAEGTAGYRVQVPQVTLSLPGAQVAGGELLVGEGVFKMPTVTVPQLELDVGLSREAQAGEAATGEGGLRLKLPTLGARARVGGEGAEEQPPGAERTFCLSLPDVELSPSGGNHAEYQVAEGEGEAGHKLKVRLPRFGLVRAKEGAEEGEKAKSPKLRLPRVGFSQSEMVTGEGSPSPEEEEEEEEEGSGEGASGRRGRVRVRLPRVGLAAPSKASRGQEGDAAPKSPVREKSPKFRFPRVSLSPKARSGSGDQEEGGLRVRLPSVGFSETGAPGPARMEGAQAAAV