TY - JOUR
T1 - A calcium-dependent interaction between calmodulin and the calponin homology domain of human IQGAP1
AU - Andrews, William J.
AU - Bradley, Conor A.
AU - Hamilton, Elaine
AU - Daly, Clare
AU - Mallon, Thérèse
AU - Timson, David J.
PY - 2012/12/1
Y1 - 2012/12/1
N2 - IQGAPs are cytoskeletal scaffolding proteins which collect information from a variety of signalling pathways and pass it on to the microfilaments and microtubules. There is a well-characterised interaction between IQGAP and calmodulin through a series of IQ-motifs towards the middle of the primary sequence. However, it has been shown previously that the calponin homology domain (CHD), located at the N-terminus of the protein, can also interact weakly with calmodulin. Using a recombinant fragment of human IQGAP1 which encompasses the CHD, we have demonstrated that the CHD undergoes a calcium ion-dependent interaction with calmodulin. The CHD can also displace the hydrophobic fluorescent probe 1-anilinonaphthalene-8-sulphonate from calcium-calmodulin, suggesting that the interaction involves non-polar residues on the surface of calmodulin. Molecular modelling identified a possible site on the CHD for calmodulin interaction. The physiological significance of this interaction remains to be discovered.
AB - IQGAPs are cytoskeletal scaffolding proteins which collect information from a variety of signalling pathways and pass it on to the microfilaments and microtubules. There is a well-characterised interaction between IQGAP and calmodulin through a series of IQ-motifs towards the middle of the primary sequence. However, it has been shown previously that the calponin homology domain (CHD), located at the N-terminus of the protein, can also interact weakly with calmodulin. Using a recombinant fragment of human IQGAP1 which encompasses the CHD, we have demonstrated that the CHD undergoes a calcium ion-dependent interaction with calmodulin. The CHD can also displace the hydrophobic fluorescent probe 1-anilinonaphthalene-8-sulphonate from calcium-calmodulin, suggesting that the interaction involves non-polar residues on the surface of calmodulin. Molecular modelling identified a possible site on the CHD for calmodulin interaction. The physiological significance of this interaction remains to be discovered.
KW - ANS displacement assay
KW - Calcium-dependent interaction
KW - CHD
KW - Cytoskeletal scaffolding protein
KW - Protein-protein crosslinking
UR - http://www.scopus.com/inward/record.url?scp=84868552585&partnerID=8YFLogxK
U2 - 10.1007/s11010-012-1438-0
DO - 10.1007/s11010-012-1438-0
M3 - Article
C2 - 22944912
AN - SCOPUS:84868552585
SN - 0300-8177
VL - 371
SP - 217
EP - 223
JO - Molecular and Cellular Biochemistry
JF - Molecular and Cellular Biochemistry
IS - 1-2
ER -