4d0o
From Proteopedia
AKAP13 (AKAP-Lbc) DH domain
Structural highlights
Function[AKP13_HUMAN] Anchors cAMP-dependent protein kinase (PKA) and acts as an adapter protein to selectively couple G alpha-13 and Rho. Augments gene activation by the estrogen receptor in an element-specific and ligand-dependent manner. Activates estrogen receptor beta by a p38 MAPK-dependent pathway. Stimulates exchange activity on Rho proteins in vitro, but not on CDC42, Ras or Rac and may bind calcium ions.[1] [2] [3] [4] Publication Abstract from PubMedThe RhoGEF domain of AKAP-Lbc (AKAP13) catalyses nucleotide exchange on RhoA and is involved in development of cardiac hypertrophy. The RhoGEF activity of AKAP-Lbc has also been implicated in cancer. We have determined the X-ray crystal structure of the complex between RhoA:GDP and the AKAP-Lbc RhoGEF (DH-PH) domain to 2.1 A resolution. The structure reveals important differences compared to related RhoGEF proteins such as Leukemia-associated RhoGEF. Nucleotide exchange assays comparing the activity of the DH-PH domain to the DH domain alone showed no role for the PH domain in nucleotide exchange, which is explained by the RhoA:AKAP-Lbc structure. Comparison to a structure of the isolated AKAP-Lbc DH domain revealed a change in conformation of the N-terminal 'GEF switch' region upon binding to RhoA. Isothermal titration calorimetry showed that AKAP-Lbc has only micromolar affinity for RhoA which combined with the presence of potential binding pockets for small molecules on AKAP-Lbc raises the possibility of targeting AKAP-Lbc with guanine nucleotide exchange factor inhibitors. The Crystal Structure of the RhoA : AKAP-Lbc DH-PH Domain Complex.,Abdul Azeez KR, Knapp S, Fernandes JM, Klussmann E, Elkins JM Biochem J. 2014 Sep 4. PMID:25186459[5] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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Categories: Allerston, C | Arrowsmith, C | Azeez, K R.Abdul | Bountra, C | Delft, F von | Edwards, A M | Elkins, J M | Klussmann, E | Knapp, S | Krojer, T | Shrestha, L | Akap-lbc | Cell cycle | Gef | Ph domain | Rhogef
