DAP-kinase調控細胞收縮力之研究
Regulation of cell traction force by DAP-kinase
Date Issued
2005
Date
2005
Author(s)
Fan, Wei-Lun
DOI
en-US
Abstract
Abstract
Traction force is important in various fundamental processes, for instance, embryonic morphogenesis, angiogenesis and wound healing. At cellular level, traction force also has a great influence on cell migration, proliferation and survival. When normal cells are placed a new environment, either they adhere well and reassemble cytoskeleton, or they move toward cell death. Generation of traction forces is involved cytoskeleton rearrangement and cell surface receptors like integrin, cadherins, selectins and other cell adhesion molecules with their signaling in all these cellular events.
In our research we use traction force microscopy to detect relative amount of forces exerted by cells, and study how the signaling event can influence the contraction. Here we demonstrated that death-associated protein kinase (DAP-kinase/DAPK) actually alters the cell traction force via regulating integrin activity.
DAPK is a 160 kDa calcium/calmodulin-dependant Ser/Thr protein kinase that promotes cell death. It appears to be located within the cell interior and regulate cell shape and movement. Overpression of DAP-kinase leads to cell death including membrane blabbing, cell rounding and the formation of autophagic vesicles. DAP-kinase contains multiple functional domains, such as kinase domain, calmodulin regulatory domain, eight ankyrin repeats, cytoskeleton binding domain and a C-terminal death domain. The deletion of calmodulin regulatory domain (ΔCaM) offers DAP-kinase a constitutively active ability. When replacing lysine with alanine in kinase domain (K42A), this technique makes a kinase inactive mutant. Previous studies of these DAP-kinase mutants showed that the cells expressing ΔCaM mutant downregulate integrin activity. In our results, overexpression of ΔCaM mutant significantly reduced the cell traction forces. On the contrary, overexpression of kinase dead mutant (K42A) had also led the increase on traction force. Moreover, to enforce activation of integrin both with activating antibody or with downstream elements, i.e., overexpression of FAK or talin F3 domain, associated downstream signals activated by integrin, both can reverse the effect. Therefore, our results clearly demonstrated that DAPK can regulate cellular traction forces from suppressing integrin activity
Subjects
死亡訊息相關分子
細胞收縮力
顯微鏡追蹤法
DAP-kinase
traction force
traction force microscopy
Type
other
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