microtubule-associated protein-7 (MAP7, ensconsin, epithelial microtubule-associated protein of 115 kD, E-MAP-115)

Function

• microtubule-stabilizing protein
  • dynamically associated with microtubles
  • association with microtubules is regulated by phosphorylation during the cell cycle
  • during interphase only phosphorylated on Ser
  • phosphorylated on Thr in mitosis
• role in reorganization of microtubules during polarization & differentiation of epithelial cells
• role in formation of intercellular contacts
• colocalization with TRPV4
  • redistribution of TRPV4 toward the membrane
  • may link cytoskeletal microfilaments

Compartment

• cytoplasm, perinuclear region, basolateral cell membrane
• colocalized on microtubules
• an intracellular redistribution is triggered during induction of keratinocyte terminal differentiation from microtubules with a perinuclear localization to peripheral microtubules organized in spike-like bundles facing intercellular contacts

Alternative splicing

named isoforms=3

Expression

• expressed in skin & cells of epithelial origin
• expressed in the suprabasal layers of the normal epidermis
• up-regulated upon terminal differentiation of primary keratinocytes

Pathology

• relatively abundant in squamous cell carcinomas
• barely detectable in basal cell carcinomas

More general terms

• microtubule-associated protein (MAP)
• phosphoprotein

Database

• OMIM: https://mirror.omim.org/entry/604108
• UniProt: http://www.uniprot.org/uniprot/Q14244.html