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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2005-5-10
pubmed:databankReference
pubmed:abstractText
Myxococcus xanthus, a Gram-negative developmental bacterium, contains a large number of protein Ser/Thr kinases (PSTKs). Among these PSTKs, Pkn4 has been shown to be 6-phosphofructokinase (PFK) kinase. PFK associates with the regulatory domain of Pkn4 (Pkn4RD) and is activated by Pkn4-mediated phosphorylation. The activation of PFK is required to consume glycogen accumulated during early development and is essential for efficient sporulation. Using the yeast two-hybrid screen, we identified three new factors, MkapA, MkapB and MkapC, that interact with Pkn4 and each contains well-known protein-protein interaction domains. MkapB contains eight tandem repeats of the TPR (tetratrico peptide repeat) domain and its interaction with Pkn4RD was phosphorylation-dependent. MkapB remained associated with Pkn4RD. As a result, Pkn4 did not interact with PFK and its activation was inhibited. While deletion of the pfk-pkn4 operon did not inhibit fruiting body formation, the spore yield was low. In contrast, a mkapB deletion mutant exhibited a 24 h delay in fruiting body formation, accumulated less glycogen in the stationary phase and gave rise to 3.2% spore formation as opposed to 100% attained with DZF1. In addition to Pkn4, MkapA associated with other membrane-associated PSTKs, Pkn1, Pkn2, Pkn8 and Pkn9, while MkapB associated with Pkn8 and Pkn9, and MkapC with Pkn8. These results indicate that there are complex PSTK networks in M. xanthus that share common modulating factors.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0950-382X
pubmed:author
pubmed:issnType
Print
pubmed:volume
56
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1314-28
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
Modulating factors for the Pkn4 kinase cascade in regulating 6-phosphofructokinase in Myxococcus xanthus.
pubmed:affiliation
Department of Biochemistry, Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't