PMID- 16645047
OWN - NLM
STAT- MEDLINE
DCOM- 20060719
LR  - 20231213
IS  - 1530-6860 (Electronic)
IS  - 0892-6638 (Linking)
VI  - 20
IP  - 8
DP  - 2006 Jun
TI  - Isoelectric points and post-translational modifications of connexin26 and 
      connexin32.
PG  - 1221-3
AB  - The isoelectric points of the gap junction proteins connexin26 (Cx26) and 
      connexin32 (Cx32) were determined by isoelectric focusing in free fluids. The 
      isoelectric points were significantly more acidic than predicted from amino acid 
      sequences and different from each other, allowing homomeric channels to be 
      resolved separately. The isoelectric points of the homomeric channels bracketed 
      the isoelectric points of heteromeric Cx26/Cx32 channels. For heteromeric 
      channels, Cx26 and Cx32 were found in overlapping, pH-focused fractions, 
      indicating quaternary structure was retained. Matrix-assisted laser 
      desorption/ionization time-of-flight mass spectrometry was used to identify 
      post-translational modifications of Cx26 and Cx32 cytoplasmic domains, including 
      the first reported post-translational modifications of Cx26. Suspected 
      modifications were hydroxylation and/or phosphorylation near the amino terminus 
      of both connexins, gamma-carboxyglutamate residues in the cytoplasmic loop of 
      both connexins, phosphorylation in the carboxyl-terminal domain of Cx32, and 
      palmitoylation at the carboxyl-terminus of Cx32. These modifications contribute 
      to the measured acidic isoelectric points of Cx26 and Cx32, whereas their low 
      molecular masses would not appreciably change connexin SDS-PAGE mobility. Most of 
      these modifications have not previously been identified for connexins and may be 
      instrumental in guiding and understanding novel aspects of channel trafficking 
      and molecular mechanisms of channel regulation.
FAU - Locke, Darren
AU  - Locke D
AD  - Department of Pharmacology and Physiology, New Jersey Medical School, 185 South 
      Orange Ave., University of Medicine and Dentistry of New Jersey, Newark, New 
      Jersey 07103, USA. lockeda@umdnj.edu
FAU - Koreen, Irina V
AU  - Koreen IV
FAU - Harris, Andrew L
AU  - Harris AL
LA  - eng
GR  - GM36044/GM/NIGMS NIH HHS/United States
GR  - GM61406/GM/NIGMS NIH HHS/United States
PT  - Journal Article
PT  - Research Support, N.I.H., Extramural
DEP - 20060427
PL  - United States
TA  - FASEB J
JT  - FASEB journal : official publication of the Federation of American Societies for 
      Experimental Biology
JID - 8804484
RN  - 0 (Connexins)
RN  - 0 (GJB2 protein, human)
RN  - 0 (Gjb2 protein, rat)
RN  - 127120-53-0 (Connexin 26)
SB  - IM
MH  - Animals
MH  - Connexin 26
MH  - Connexins/*chemistry/*metabolism
MH  - HeLa Cells
MH  - Humans
MH  - Isoelectric Focusing
MH  - Isoelectric Point
MH  - Mice
MH  - Protein Processing, Post-Translational
MH  - Rats
MH  - Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
MH  - Gap Junction beta-1 Protein
EDAT- 2006/04/29 09:00
MHDA- 2006/07/20 09:00
CRDT- 2006/04/29 09:00
PHST- 2006/04/29 09:00 [pubmed]
PHST- 2006/07/20 09:00 [medline]
PHST- 2006/04/29 09:00 [entrez]
AID - fj.05-5309fje [pii]
AID - 10.1096/fj.05-5309fje [doi]
PST - ppublish
SO  - FASEB J. 2006 Jun;20(8):1221-3. doi: 10.1096/fj.05-5309fje. Epub 2006 Apr 27.