Recombinant Rat Microtubule-associated protein tau (Mapt) (Active)

Function

Promotes microtubule assembly and stability, and might be involved in the establishment and maintenance of neuronal polarity. The C-terminus binds axonal microtubules while the N-terminus binds neural plasma membrane components, suggesting that tau functions as a linker protein between both. Axonal polarity is predetermined by tau localization (in the neuronal cell) in the domain of the cell body defined by the centrosome. The short isoforms allow plasticity of the cytoskeleton whereas the longer isoforms may preferentially play a role in its stabilization

Subcellular Location

Cytoplasm, cytosol; Cell membrane (Peripheral membrane protein); Cytoplasm, cytoskeleton; Cell projection, axon; Cell projection, dendrite; Secreted

Tissue Specificity

Expressed in neurons. The larger forms (isoform tau-A and isoform tau-B) are preferentially expressed in the peripheral nervous system while the other are expressed in the central nervous system. Low amounts of the larger forms are also found in limited areas of the CNS

Subunit

Interacts with MARK1, MARK2, MARK3 and MARK4 (By similarity). Interacts with SQSTM1 when polyubiquitinated (By similarity). Interacts with PSMC2 through SQSTM1 (By similarity). Interacts with FKBP4 (PubMed:20133804). Binds to CSNK1D (By similarity). Interacts with SGK1 (By similarity). Interacts with EPM2A; the interaction dephosphorylates MAPT at Ser-388 (By similarity). Interacts with PIN1 (By similarity). Interacts with LRRK2 (By similarity). Interacts with LRP1, leading to endocytosis; this interaction is reduced in the presence of LRPAP1/RAP (By similarity)

• Goedert M. et al. Cloning of a big tau microtubule-associated protein characteristic of the peripheral nervous system. — Proc. Natl. Acad. Sci. U.S.A. (1992)
• Georgieff I.S. et al. Expression of high molecular weight tau in the central and peripheral nervous systems. — J. Cell Sci. (1993)
• Sadot E. et al. Complete sequence of 3'-untranslated region of tau from rat central nervous system. Implications for mRNA heterogeneity. — J. Mol. Biol. (1994)
• Kosik K.S. et al. Developmentally regulated expression of specific tau sequences. — Neuron (1989)
• Kanai Y. et al. Expression of multiple tau isoforms and microtubule bundle formation in fibroblasts transfected with a single tau cDNA. — J. Cell Biol. (1989)
• Mavilia C. et al. Diversity of high-molecular-weight tau proteins in different regions of the nervous system. — J. Neurochem. (1994)
• Watanabe A. et al. In vivo phosphorylation sites in fetal and adult rat tau. — J. Biol. Chem. (1993)
• Sawa A. et al. Molecular diversity at the carboxyl terminus of human and rat tau. — Brain Res. Mol. Brain Res. (1994)