Significance of the C-terminal globular domain and the extra tail of the calmodulin-like protein (Pinctada fucata) in subcellular localization and protein-protein interaction.
Calmodulin (CaM) plays a very important role in many physiological processes and is highly conserved in different species. In a previous study, we successfully cloned CaM and a novel calmodulin-like protein (CaLP) with an extra C-terminal sequence from the pearl oyster Pinctada fucata and then expressed in Escherichia coli. In this research, we used fluorescence confocal microscopy to analyze the protein-protein interaction between CaM/CaLP and p21Cip1, which is cloned from mammalian cells, to show the different characteristics of these two proteins in vivo. The fluorescence confocal microscopy showed that the C-terminal globular domain together with the extra tail of CaLP is very important in CaLP's sequestration in cytoplasm. The most interesting phenomenon is that transfection of p21Cip1 can stimulate translocation of CaLP from the cytoplasm to the nucleus, but this is not the case for CaM. Fluorescence confocal microscopy and co-immunoprecipitation on different mutants of CaLP with p21Cip1 indicated that the C-terminal globular domain of CaLP is responsible for the trafficking of CaLP from cytoplasm to nucleus.
Fang
Zi
Z
Institute of Marine Biotechnology, Department of Biological Science and Biotechnology, Tsinghua University, Haidian, Beijing 100084, PR China.
Cao
Weizhong
W
Li
Shuo
S
Wang
Qin
Q
Li
Changzhong
C
Xie
Liping
L
Zhang
Rongqing
R
D021581:Active Transport, Cell Nucleus; D000818:Animals; D002147:Calmodulin / Q000737:chemistry* / Q000378:metabolism*; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism*; D003001:Cloning, Molecular; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism*; D006801:Humans; D049911:Pinctada; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D014162:Transfection
D002147:Calmodulin; D050759:Cyclin-Dependent Kinase Inhibitor p21