mitotic spindle assembly checkpoint protein MAD1 (mitotic arrest deficient-like protein 1, MAD1-like 1, mitotic checkpoint MAD1 protein-homolog, HsMAD1, hMAD1, Tax-binding protein 181, MAD1L1, MAD1, TXBP181)

Function

• component of the spindle-assembly checkpoint
• role in the correct positioning of the septum
• anchoring MAD2L1 to the nuclear periphery
• forms tetrameric MAD1L1-MAD2L1 complex
• CDC20 can compete with MAD1L1 for MAD2L1 binding, until attachment &/or tension dampen the checkpoint signal
• able to interact with the BUB1/BUB3 complex
• induced by Tp53
• phosphorylated by BUB1
  • become hyperphosphorylated in late S phase through M phase or after mitotic spindle damage

Compartment

• nucleus
• moves from diffusely nuclear distribution to the centrosome, to the spindle midzone & finally to the midbody during mitosis

Alternative splicing

named isoforms=2

Expression

• expressed weakly at G0/G1 & highly at late S phase & G2/M phase

Pathology

• interacts with viral Tax protein
• defects in MAD1L1 are involved in development &/or progression of various types of cancer

More general terms

• nuclear protein
• phosphoprotein

Component of

• spindle-assembly checkpoint

Database

• OMIM: https://mirror.omim.org/entry/602686
• UniProt: http://www.uniprot.org/uniprot/Q9Y6D9.html