title: AP4B1
text: # AP4B1
  
  AP-4 complex subunit beta-1 is a protein that in humans is encoded by the AP4B1 gene.
  
  ## Function
  
  The heterotetrameric adaptor protein (AP) complexes sort integral membrane proteins at various stages of the endocytic and secretory pathways. AP4 is composed of 2 large chains, beta-4 (AP4B1, this protein) and epsilon-4 (AP4E1), a medium chain, mu-4 (AP4M1), and a small chain, sigma-4 (AP4S1)
  
  ## Interactions
  
  AP4B1 has been shown to interact with AP4M1.
  
  ## Clinical relevance
  
  AP4-complex-mediated trafficking plays a crucial role in brain development and functioning.
  
  