Distribution of dystrophin- and utrophin-associated protein complexes during activation of human neutrophils.
OBJECTIVE
Dystrophins, utrophins, and their associated proteins are involved in structural and signaling roles in nonmuscle tissues; however, description of these proteins in neutrophils remained unexplored. Therefore we characterize the pattern expression, and the cellular distribution of dystrophin and utrophin gene products and dystrophin-associated proteins (i.e., beta-dystroglycan, alpha-syntrophin, and alpha-dystrobrevins) in relation to actin filaments in resting and activated with formyl-methionyl-leucyl-phenylalanine human neutrophils.


METHODS
Resting and fMLP-activated human neutrophils were analyzed by immunoblot and by confocal microscopy analysis. Immunoprecipitation assays were performed to corroborate the presence of protein complexes.


RESULTS
Immunoprecipitation assays and confocal analysis demonstrated the presence of two dystrophin-associated protein complexes in resting and activated neutrophils: the former formed by Dp71d/Dp71Delta(110)(m) and dystrophin-associated proteins (beta-dystroglycan, alpha-syntrophin, alpha-dystrobrevin-1, and -2), while the latter contains Up400, instead of Dp71d/Dp71Delta(110)(m), as a central component of the dystrophin-associated protein complexes (DAPC). Confocal analysis also showed the subcellular redistribution of Dp71d/Dp71Delta(110)(m) approximately DAPC and Up400 approximately DAPC in F-actin-based structures displayed during activation process with fMLP.


CONCLUSIONS
Our study showed the existence of two protein complexes formed by Dp71d/Dp71Delta(110)(m) or Up400 associated with DAPs in resting and fMLP-treated human polymorphonuclears. The interaction of these complexes with the actin cytoskeleton is indicative of their dynamic participation in the chemotaxis process.
Cerecedo
Doris
D
Instituto Politécnico Nacional, México, D.F., México. dcereced@prodigy.net.mx
Cisneros
Bulmaro
B
Gómez
Pablo
P
Galván
Iván J
IJ
D000199:Actins / Q000378:metabolism; D002135:Calcium-Binding Proteins / Q000378:metabolism; D002633:Chemotaxis / Q000187:drug effects / Q000502:physiology; D003599:Cytoskeleton / Q000378:metabolism; D049030:Dystroglycans / Q000378:metabolism; D016189:Dystrophin / Q000378:metabolism*; D049029:Dystrophin-Associated Proteins / Q000378:metabolism; D006801:Humans; D008565:Membrane Proteins / Q000378:metabolism; D046912:Multiprotein Complexes / Q000378:metabolism*; D009124:Muscle Proteins / Q000378:metabolism; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D018375:Neutrophil Activation / Q000187:drug effects / Q000502:physiology*; D009504:Neutrophils / Q000378:metabolism*; D049411:Utrophin / Q000378:metabolism*
D000199:Actins; D002135:Calcium-Binding Proteins; C484258:DMD protein, human; D016189:Dystrophin; D049029:Dystrophin-Associated Proteins; D008565:Membrane Proteins; D046912:Multiprotein Complexes; D009124:Muscle Proteins; C483599:UTRN protein, human; D049411:Utrophin; C098885:dystrobrevin; C091825:syntrophin alpha1; D049030:Dystroglycans; D009240:N-Formylmethionine Leucyl-Phenylalanine