Structures of the LGN/NuMA complex
[NUMA1_HUMAN] Acute promyelocytic leukemia.
[GPSM2_MOUSE] Plays an important role in spindle pole orientation (By similarity). Interacts and contributes to the functional activity of G(i) alpha proteins. Acts to stabilize the apical complex during neuroblast divisions. [NUMA1_HUMAN] Highly abundant component of the nuclear matrix where it may serve a non-mitotic structural role, occupies the majority if the nuclear volume. Required for maintenance and establishment of the mitotic spindle poles, functionning as a tether linking bulk microtubules of the spindle to centrosomes. May be involved in coordination of the alignment of the mitotic spindle to the cellular polarity axis, which is a prerequisite for asymmetric cell divisions.
Publication Abstract from PubMed
Asymmetric cell division requires the establishment of cortical cell polarity and the orientation of the mitotic spindle along the axis of cell polarity. Evidence from invertebrates demonstrates that the Par3/Par6/aPKC and NuMA/LGN/Galphai complexes, which are thought to be physically linked by the adaptor protein mInscuteable (mInsc), play indispensable roles in this process. However, the molecular basis for the binding of LGN to NuMA and mInsc is poorly understood. The high-resolution structures of the LGN/NuMA and LGN/mInsc complexes presented here provide mechanistic insights into the distinct and highly specific interactions of the LGN TPRs with mInsc and NuMA. Structural comparisons, together with biochemical and cell biology studies, demonstrate that the interactions of NuMA and mInsc with LGN are mutually exclusive, with mInsc binding preferentially. Our results suggest that the Par3/mInsc/LGN and NuMA/LGN/Galphai complexes play sequential and partially overlapping roles in asymmetric cell division.
LGN/mInsc and LGN/NuMA complex structures suggest distinct functions in asymmetric cell division for the Par3/mInsc/LGN and Galphai/LGN/NuMA pathways.,Zhu J, Wen W, Zheng Z, Shang Y, Wei Z, Xiao Z, Pan Z, Du Q, Wang W, Zhang M Mol Cell. 2011 Aug 5;43(3):418-31. PMID:21816348
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.