The Ankrd 13 family of UIM-bearing proteins regulates EGF receptor endocytosis from the plasma membrane.
-
ANKRD13D binds Lys63- but not Lys48-linked chains.
"As shown in Figure 4A, Ankrd 13A, 13B, and 13D, but not 13C, pulled down Lys-63–linked, but not Lys-48–linked, Ub chains."
-
Endogenous ANKRD13D binds EGFR after EGF.
"Blotting of the precipitates with the anti–Ankrd 13 antibodies showed that endogenous Ankrd 13A and 13D, but not 13C, bind to EGFR upon EGF treatment with the same time course as transfected Ankrd 13 proteins (Figure 2B)."
-
Endogenous ANKRD13D is at the plasma membrane, increased by EGF.
"Similarly, endogenous Ankrd 13A and 13D, but not 13C, were coprecipitated with biotinylated molecules from untransfected cells, and the amounts of plasma membrane-bound endogenous 13A and 13D were elevated after 5 min of EGF stimulation (Figure 6B)."
-
Overexpression retains EGFR at the surface.
"In striking contrast, EGFR was mostly retained at the surface in cells overexpressing FLAG-tagged Ankrd 13A, 13B, or 13D (Figure 7, C–E′′)."
-
The sign of regulation is open because dominant-negative truncations also inhibit.
"raising the question of whether Ankrd 13 proteins have a stimulatory or inhibitory role in the process"
-
The authors propose a positive role in EGFR internalization.
"we propose that Ankrd 13A, 13B, and 13D positively regulate the internalization of ligand-activated EGFR"
-
ANKRD13D only marginally colocalizes with a late endosome marker.
"Ankrd 13D marginally colocalized with CI-M6PR (Supplemental Figure S1, C–C′′)."