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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1-2
pubmed:dateCreated
2011-3-15
pubmed:abstractText
Caldesmon (CaD) is an actin-binding protein that is capable of stabilizing actin filaments. Phosphorylation of CaD is widely accepted in the actin cytoskeletal modeling and promotion of cell migration. In this study, we show that CaD is a downstream phosphorylation substrate of PFTK1, a novel Cdc-2-related ser/thr protein kinase. Our study stemmed from an earlier investigation where we demonstrated that PFTK1 kinase conferred cell migratory advantages in human hepatocellular carcinoma (HCC) cells. Here, we showed that PFTK1-knockdown cells exhibited much reduced CaD phosphorylation and consequently caused dissociation of CaD from the F-actin fibers. The cellular localization of CaD was also altered in the absence of PFTK1. Immunofluorescence analysis revealed that PFTK1-abrogated cells exhibited a diffused and blurred appearance of CaD localization, whereas intact co-localization with F-actins was apparent in PFTK1-expressing cells. Without the binding of CaD to actin, disappearance of actin stress fibers was also evident in PFTK1-abrogated cells. In addition, we found that CaD is also commonly up-regulated in HCC tumors when compared to adjacent non-malignant liver (P = 0.022). Taken together, our results highlight a novel biological cascade that involved the phosphorylation activation of CaD by PFTK1 kinase in promoting formation of actin stress fibers.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
1573-4919
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
350
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
201-6
pubmed:meshHeading
pubmed:year
2011
pubmed:articleTitle
Phosphorylation of Caldesmon by PFTAIRE1 kinase promotes actin binding and formation of stress fibers.
pubmed:affiliation
Department of Anatomical and Cellular Pathology, Prince of Wales Hospital, Chinese University of Hong Kong, Shatin, N. T, Hong Kong, China.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't