Table 1.

Localization of proteins of the PAR-aPKC complex in different species

C. elegansDrosophila Mammal
S. pombeC. elegansDrosophila Mammal zygote late oocyte epithelia neuroblast epithelia
PAR-3 Bazooka PAR-3/ASIP* Anterior cortex Anterior cortex SAR/apical membrane Apical cortex TJ apical membrane
PAR-6 PAR-6 PAR-6α,β,γ
PKC-3 aPKC aPKCλ,ζ
Kin1 PAR-1 PAR-1 PAR-1a/MARK3/C-TAK Posterior cortex Posterior cortex Basolateral membrane ? Basolateral membrane
PAR-2 Posterior cortex
PAR-4 LKB1 LKB1/STK11 Uniformly cytoplasmic (faintly cortical) (Uniformly cortical) (Uniformly cortical) ? (Uniformly membraneous)§
BMH1/2 PAR-5 14-3-3ϵ/Leo 14-3-3β,γ,ϵ,η,ζ Uniformly cytoplasmic Cytoplasm Cytoplasm ? (Uniformly cytoplasmic/membraneous)
  • SAR, subapical region; TJ, tight junction. Parentheses indicate the localization of overexpressed protein. See text for details. For the localization of PAR-4 and PAR-5/14-3-3, see the following references: PAR-4 (Martin and St Johnston, 2003; Watts et al., 2000); PAR-5/14-3-3 (Benton et al., 2002; Hurd et al., 2003a; Morton et al., 2002).

  • * In mammals, the PAR-3-related protein PAR-3L, showing an overall homology with PAR-3, has been identified (Gao et al., 2002). Although its characterization is limited, it has been shown to localize to TJs when overexpressed; it cannot bind to aPKC

  • As discussed in the text, the localization of PAR-3 often slightly differs from that of aPKC and/or PAR-6. In particular, in mammalian epithelial cells, PAR-3 tends to show a clearer concentration in TJs than do aPKC and PAR-6

  • MARK4/MARKL1 is not included because this variant of mammalian PAR-1 does not show asymmetric localization in mammalian epithelial cells when overexpressed (A.S. and S.O., unpublished)

  • § A.S. and S.O., unpublished

  • 14-3-3 isoforms for which the interaction with PAR-1b was confirmed are only listed (M. Hirata, A.S. and S.O., unpublished)