Fig. 2.

Glycosylation of BMPRIA contributes to its folding. HEK293T cells were transfected with myc-tagged constructs of: a wild-type RIA (R1A-WT) or its glycosylation-negative mutant (R1A-N73A): b R1B-1S1-WT or c glycosylation-gain mutants of R1B isoforms (R1B-1S1-146T R1B-IS2-176T), Cells were lysed at 24 h post-transfection and lysates were digested with EndoH (E) or PNGaseF (P) and separated by SDS-PAGE. Immunoblots were analyzed with anti-myc antibody. >>, EndoH-resistant receptors containing mature glycosyl chains; >, unglycosylated precursor receptors; *, non-specific band. d HEK293T cells were transfected with HA-tagged R1B-IS1-WT, R1B-IS1-146T, R1A-WT or R1A-N73A. Cell lysates (24 h post-transfection) were separated by SDS-PAGE under reducing (+) or non-reducing (−) conditions. Immunoblots were probed with anti-HA antibodies. Numbers below brackets are the percentage of disulfide-bonded oligomers relative to total amount of receptor signal in the non-reducing lane