PMID- 10608890
OWN - NLM
STAT- MEDLINE
DCOM- 20000208
LR  - 20210209
IS  - 0021-9258 (Print)
IS  - 0021-9258 (Linking)
VI  - 274
IP  - 53
DP  - 1999 Dec 31
TI  - The retinal rod Na(+)/Ca(2+),K(+) exchanger contains a noncleaved signal sequence 
      required for translocation of the N terminus.
PG  - 38177-82
AB  - The retinal rod Na(+)/Ca(2+),K(+) exchanger (RodX) is a polytopic membrane 
      protein found in photoreceptor outer segments where it is the principal extruder 
      of Ca(2+) ions during light adaptation. We have examined the role of the 
      N-terminal 65 amino acids in targeting, translocation, and integration of the 
      RodX using an in vitro translation/translocation system. cDNAs encoding human 
      RodX and bovine RodX through the first transmembrane domain were correctly 
      targeted and integrated into microsomal membranes; deletion of the N-terminal 65 
      amino acids (aa) resulted in a translation product that was not targeted or 
      integrated. Deletion of the first 65 aa had no effect on membrane targeting of 
      full-length RodX, but the N-terminal hydrophilic domain no longer translocated. 
      Chimeric constructs encoding the first 65 aa of bovine RodX fused to globin were 
      translocated across microsomal membranes, demonstrating that the sequence could 
      function heterologously. Studies of fresh bovine retinal extracts demonstrated 
      that the first 65 aa are present in the native protein. These data demonstrate 
      that the first 65 aa of RodX constitute an uncleaved signal sequence required for 
      the efficient membrane targeting and proper membrane integration of RodX.
FAU - McKiernan, C J
AU  - McKiernan CJ
AD  - Department of Cell Biology, The Scripps Research Institute, La Jolla, California 
      92037, USA.
FAU - Friedlander, M
AU  - Friedlander M
LA  - eng
GR  - 5F32 EY06820/EY/NEI NIH HHS/United States
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - United States
TA  - J Biol Chem
JT  - The Journal of biological chemistry
JID - 2985121R
RN  - 0 (Carrier Proteins)
RN  - 0 (Protein Sorting Signals)
RN  - 0 (Sodium-Calcium Exchanger)
RN  - 147478-17-9 (potassium-dependent sodium-calcium exchanger)
SB  - IM
MH  - Animals
MH  - Biological Transport
MH  - Blotting, Western
MH  - Carrier Proteins/chemistry/genetics/*metabolism
MH  - Cattle
MH  - Cloning, Molecular
MH  - Intracellular Membranes/metabolism
MH  - Microsomes/metabolism
MH  - Protein Sorting Signals/*chemistry
MH  - Rod Cell Outer Segment/*metabolism
MH  - *Sodium-Calcium Exchanger
EDAT- 1999/12/23 00:00
MHDA- 1999/12/23 00:01
CRDT- 1999/12/23 00:00
PHST- 1999/12/23 00:00 [pubmed]
PHST- 1999/12/23 00:01 [medline]
PHST- 1999/12/23 00:00 [entrez]
AID - S0021-9258(19)53010-1 [pii]
AID - 10.1074/jbc.274.53.38177 [doi]
PST - ppublish
SO  - J Biol Chem. 1999 Dec 31;274(53):38177-82. doi: 10.1074/jbc.274.53.38177.