Spatially resolved quantification of E-cadherin on target hES cells.
The local expression and distribution pattern of protein on a cell play essential roles in signal transduction within a cell or between cells. Here we report on the development of a spatially resolved quantification method, which was applied in the study of E-cadherin local expression in identified undifferentiated and differentiated human embryonic stem (hES) cells in their native cellular environment. This was achieved by a novel immunofluorescence assisted affinity mapping (IF-AM) method, in which immunofluorescence provides the guidance to locate a desired type of cell in a cell community for performing affinity mapping to quantify the local protein density. The results unveiled the crucial role of E-cadherin in mediating hES cell proliferation and differentiation: the expression of E-cadherin is markedly higher on undifferentiated cells, and the growth of hES cells in unique colonies is contingent on the homogeneous distribution of E-cadherin. Due to the ability of directly assessing individual proteins of a cell, the IF-AM method is shown to be a sensitive tool for resolving subtle differences in the local expression of membrane proteins even at low abundance.
Department of Biological, Chemical, and Physical Sciences, Illinois Institute of Technology, Chicago, Illinois 60616, USA.
Zhaoxia
Z
Li
Dengli
D
Qiu
Indumathi
I
Sridharan
Xiaoping
X
Qian
Honghong
H
Zhang
Chunbo
C
Zhang
Rong
R
Wang
D015820:Cadherins / Q000096:biosynthesis / Q000737:chemistry*; D002478:Cells, Cultured; D053595:Embryonic Stem Cells / Q000737:chemistry* / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D006801:Humans
D015820:Cadherins