title: Brain-type creatine kinase BB-CK interacts with the Golgi Matrix Protein GM130 in early prophase.
abstract: Creatine kinase (CK) isoenzymes are essential for storing, buffering and intracellular transport of "energy-rich" phosphate compounds in tissues with fluctuating high energy demand such as muscle, brain and other tissues and cells where CK is expressed. In brain and many non-muscle cells, ubiquitous cytosolic "brain-type" BB-CK and ubiquitous mitochondrial CK (uMtCK) act as components of a phosphocreatine shuttle to maintain cellular energy pools and distribute energy flux. To date, still relatively little is known about direct coupling of functional dimeric BB-CK with other partner proteins or enzymes that are important for cell function. Using a global yeast two-hybrid (Y2H) screen with monomeric B-CK as bait and a representative brain cDNA library to search for interaction partners of B-CK with proteins of the brain, we repeatedly identified the cis-Golgi Matrix protein (GM130) as recurrent interacting partner of B-CK. Since HeLa cells also express both BB-CK and GM130, we subsequently used this cellular model system to verify and characterize the BB-CK-GM130 complex by GST-pulldown experiments, as well as by in vivo co-localization studies with confocal microscopy. Using dividing HeLa cells, we report here for the first time that GM130 and BB-CK co-localize specifically in a transient fashion during early prophase of mitosis, when GM130 plays an important role in Golgi fragmentation that starts also at early prophase. These data may shed new light on BB-CK function for energy provision for Golgi-fragmentation that is initiated by cell signalling cascades in the early phases of mitosis.
authors.affiliation: Institute of Cell Biology, HPM D24, ETH ZURICH, Schafmattstr. 18, Zurich 8093, Switzerland.
authors.forename: Tanja S
authors.initials: TS
authors.lastname: Bürklen
authors.forename: Alain
authors.initials: A
authors.lastname: Hirschy
authors.forename: Theo
authors.initials: T
authors.lastname: Wallimann
mesh_terms: D000596:Amino Acids; D000818:Animals; D001324:Autoantigens / Q000737:chemistry / Q000378:metabolism*; D020126:Brefeldin A / Q000494:pharmacology; D052276:Creatine Kinase, BB Form / Q000378:metabolism*; D006056:Golgi Apparatus / Q000187:drug effects / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D008565:Membrane Proteins / Q000737:chemistry / Q000378:metabolism*; D011418:Prophase / Q000187:drug effects; D011485:Protein Binding / Q000187:drug effects; D017434:Protein Structure, Tertiary; D021381:Protein Transport / Q000187:drug effects; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D020798:Two-Hybrid System Techniques
chemical_list: D000596:Amino Acids; D001324:Autoantigens; C097741:Golgin subfamily A member 2; D008565:Membrane Proteins; D011993:Recombinant Fusion Proteins; D020126:Brefeldin A; D052276:Creatine Kinase, BB Form