Myristoylated and non-myristoylated forms of the pH sensor protein hisactophilin II: intracellular shuttling to plasma membrane and nucleus monitored in real time by a fusion with green fluorescent protein.
Hisactophilins are myristoylated proteins that are rich in histidine residues and known to exist in Dictyostelium cells in a plasma membrane-bound and a soluble cytoplasmic state. Intracellular translocation of these proteins in response to pH changes was monitored using hisactophilin fusions with green fluorescent protein (GFP) and confocal laser scanning microscopy. Both the normal and a mutated non-myristoylated fusion protein shuffled within the cells in a pH-dependent manner. After lowering the pH, these proteins translocated within minutes between the cytoplasm, the plasma membrane and the nucleus. The role of histidine clusters on the surface of hisactophilin molecules in binding of the proteins to the plasma membrane and in their transfer to the nucleus is discussed on the basis of a pH switch mechanism.
Hanakam
F
F
Max-Planck-Institut für Biochemie, Germany.
Albrecht
R
R
Eckerskorn
C
C
Matzner
M
M
Gerisch
G
G
D000199:Actins / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D001692:Biological Transport; D002352:Carrier Proteins / Q000737:chemistry / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D002467:Cell Nucleus / Q000378:metabolism*; D004023:Dictyostelium / Q000378:metabolism; D005656:Fungal Proteins / Q000737:chemistry / Q000378:metabolism*; D049452:Green Fluorescent Proteins; D006863:Hydrogen-Ion Concentration; D008164:Luminescent Proteins / Q000378:metabolism*; D008840:Microfilament Proteins; D008969:Molecular Sequence Data; D019814:Myristic Acid; D009227:Myristic Acids / Q000378:metabolism; D011485:Protein Binding; D015800:Protozoan Proteins; D013997:Time Factors
D000199:Actins; D002352:Carrier Proteins; D005656:Fungal Proteins; D008164:Luminescent Proteins; D008840:Microfilament Proteins; D009227:Myristic Acids; D015800:Protozoan Proteins; D019814:Myristic Acid; C058561:hisactophilin protein, Protozoan; D049452:Green Fluorescent Proteins