Skip to main content
. Author manuscript; available in PMC: 2016 Jan 7.
Published in final edited form as: Science. 2015 Jul 10;349(6244):187–191. doi: 10.1126/science.aab1091

Fig. 3. Structure-guided identification of functional residues in human Insig-2.

Fig. 3

(A) The recombinantly expressed human Insig-2 interacts with the transmembrane domain of mouse Scap (mScap-TMD) in a 25HC-dependent manner. The recombinant proteins of Insig-2 and mScap-TMD were overexpressed in baculovirus-infected Sf-9 cells. (B) Examination of the previously identified functional residues using the insect cell assay system. Consistent with the previous report (24), single point mutations F115A, Q132Q, W145A, and D149A led to loss of Scap binding even in the presence of 25HC. (C) Identification of additional Insig-2 residues that are involved in the 25HC-dependent Scap binding. The three residues Ala113/Gly117/His120 are outward-facing residues on TM3. Single point mutations of these residues led to diminished Scap binding even in the presence of 25HC. In contrast, substitution of Val114 and Val116 with Phe retained complex formation with Scap. Shown here are representative results of at least three repeating experiments.