GONUTS has been updated to MW1.31 Most things seem to be working but be sure to report problems.

Have any questions? Please email us at ecoliwiki@gmail.com

PMID:14593072

From GONUTS
Jump to: navigation, search
Citation

Sun, B, Ma, H and Firtel, RA (2003) Dictyostelium stress-activated protein kinase alpha, a novel stress-activated mitogen-activated protein kinase kinase kinase-like kinase, is important for the proper regulation of the cytoskeleton. Mol. Biol. Cell 14:4526-40

Abstract

Mitogen-activated protein kinase cascades regulate various cellular functions, including growth, cell differentiation, development, and stress responses. We have identified a new Dictyostelium kinase (stress-activated protein kinase [SAPK]alpha), which is related to members of the mixed lineage kinase class of mitogen-activated protein kinase kinases. SAPKalpha is activated by osmotic stress, heat shock, and detachment from the substratum and by a membrane-permeable cGMP analog, a known regulator of stress responses in Dictyostelium. SAPKalpha is important for cellular resistance to stresses, because SAPKalpha null cells exhibit reduced viability in response to osmotic stress. We found that SAPKalpha mutants affect cellular processes requiring proper regulation of the actin cytoskeleton, including cell motility, morphogenesis, cytokinesis, and cell adhesion. Overexpression of SAPKalpha results in highly elevated basal and chemoattractant-stimulated F-actin levels and strong aggregation and developmental defects, including a failure to polarize and chemotax, and abnormal morphogenesis. These phenotypes require a kinase-active SAPKalpha. SAPKalpha null cells exhibit reduced chemoattractant-stimulated F-actin levels, cytokinesis, developmental and adhesion defects, and a motility defect that is less severe than that exhibited by SAPKalpha-overexpressing cells. SAPKalpha colocalizes with F-actin in F-actin-enriched structures, including membrane ruffles and pseudopodia during chemotaxis. Although SAPKalpha is required for these F-actin-mediated processes, it is not detectably activated in response to chemoattractant stimulation.

Links

PubMed PMC266770 Online version:10.1091/mbc.E03-01-0039

Keywords

Actins/genetics; Actins/metabolism; Amino Acid Sequence; Animals; Cell Adhesion; Cell Division; Cell Movement/drug effects; Cell Movement/genetics; Cell Movement/physiology; Cell Survival/genetics; Cell Survival/physiology; Cloning, Molecular; Cyclic AMP/pharmacology; Cytoskeleton/genetics; Cytoskeleton/metabolism; Dictyostelium/cytology; Dictyostelium/genetics; Dictyostelium/metabolism; MAP Kinase Kinase Kinases/genetics; MAP Kinase Kinase Kinases/metabolism; Molecular Sequence Data; Morphogenesis; Mutation; Osmotic Pressure; Sequence Analysis, Protein

Significance

Annotations

Gene product Qualifier GO Term Evidence Code with/from Aspect Extension Notes Status

DICDI:SPKA

acts_upstream_of_or_within

GO:0030036: actin cytoskeleton organization

ECO:0000315: mutant phenotype evidence used in manual assertion

P

Seeded From UniProt

complete

DICDI:SPKA

acts_upstream_of_or_within

GO:0000281: mitotic cytokinesis

ECO:0000315: mutant phenotype evidence used in manual assertion

P

Seeded From UniProt

complete

DICDI:SPKA

located_in

GO:0015629: actin cytoskeleton

ECO:0000314: direct assay evidence used in manual assertion

C

Seeded From UniProt

complete

DICDI:SPKA

located_in

GO:0005737: cytoplasm

ECO:0000314: direct assay evidence used in manual assertion

C

Seeded From UniProt

complete

DICDI:SPKA

involved_in

GO:0006970: response to osmotic stress

ECO:0000314: direct assay evidence used in manual assertion

P

Seeded From UniProt

complete

DICDI:SPKA

acts_upstream_of_or_within

GO:0006935: chemotaxis

ECO:0000315: mutant phenotype evidence used in manual assertion

P

Seeded From UniProt

complete

DICDI:SPKA

enables

GO:0004672: protein kinase activity

ECO:0000314: direct assay evidence used in manual assertion

F

Seeded From UniProt

complete

DICDI:SPKA

acts_upstream_of_or_within

GO:0050793: regulation of developmental process

ECO:0000315: mutant phenotype evidence used in manual assertion

P

Seeded From UniProt

complete


See also

References

See Help:References for how to manage references in GONUTS.