Title : Glycosylation of the osmoresponsive transient receptor potential
channel TRPV4 on
Asn-651 influences membrane trafficking
Abstract :
- We identified a consensus N-linked glycosylation motif within the pore-forming loop between the fifth and sixth transmembrane segments of the osmoresponsive transient receptor potential ( TRP ) channel TRPV4
- Mutation of this residue from Asn to Gln (i.e., TRPV4 ( N651Q )) resulted in loss of a slower migrating band on anti- TRPV4 immunoblots and a marked reduction in lectin-precipitable TRPV4 immunoreactivity
- HEK293 cells transiently transfected with the mutant TRPV4 ( N651Q ) exhibited increased calcium entry in response to hypotonic stress relative to wild-type TRPV4 transfectants
- This increase in hypotonicity responsiveness was associated with an increase in plasma membrane targeting of TRPV4 ( N651Q ) relative to wild-type TRPV4 in both HEK293 and COS-7 cells but had no effect on overall channel abundance in whole cell lysates
- Residue N651 of TRPV4 is immediately adjacent to the pore-forming loop
- Although glycosylation in this vicinity has not been reported for a TRP channel , the structurally related hexahelical hyperpolarization-activated cyclic nucleotide-gated channel , HCN2 , and the voltage-gated potassium channel , human ether-a-go-go-related ( HERG ), share a nearly identically situated and experimentally confirmed N-linked glycosylation site which promotes rather than limits channel insertion into the plasma membrane
- These data point to a potentially conserved structural and functional feature influencing membrane trafficking across diverse members of the voltage-gated-like ion channel superfamily
Output (sent_index, trigger,
protein,
sugar,
site):
- 0. Glycosylation, , TRPV4, -, -
- 1. glycosylation, , -, -, motif
- 6. glycosylation, , -, -, site
Output(Part-Of) (sent_index,
protein,
site):
*Output_Site_Fusion* (sent_index,
protein,
sugar,
site):