Document Detail

Cloning and functional characterization of squid voltage-dependent Ca2+ channel beta subunits: involvement of N-terminal sequences in differential modulation of the current.
MedLine Citation:
PMID:  12725917     Owner:  NLM     Status:  MEDLINE    
cDNAs that encode beta subunits of voltage-dependent Ca(2+) channel were cloned from the optic lobe of the squid Loligo bleekeri. The subunits, LoCa(v)beta(1a) and LoCa(v)beta(1b) are 96% identical in amino acid sequence. The sole sequence differences are in the N-terminal region and in a five amino acid insertion in the central region of LoCa(v)beta(1b). RT-PCR revealed that LoCa(v)beta(1a) and LoCa(v)beta(1b) transcripts were expressed mainly in the optic lobe and stellate ganglion, and more weakly in mantle muscle, systemic heart, gill, branchial heart, stomach and liver. Coexpression of LoCa(v)beta(1a) or LoCa(v)beta(1b) with mammalian Ca(v)2.3 and alpha(2)/delta subunits in the Xenopus oocyte resulted in high-voltage-activated currents, and showed slow current inactivation and moderate steady-state inactivation. Comparison of the squid subunits with four mammalian beta subunits, beta(1b), beta(2a), beta(3) and beta(4), demonstrated that the modulatory effects of the beta subunits on steady-state inactivation kinetics were beta(3)<beta(4) approximately beta(1b)<LoCa(v)beta(1a) approximately LoCa(v)beta(1b)<beta(2a). LoCa(v)beta(1a)-induced current amplitude was about two to four times higher than that of LoCa(v)beta(1b). Experiments with point mutants and chimeras suggest that potential PKC and CK2 phosphorylation sites in the N-terminal region of LoCa(v)beta(1b) affect the current amplitude reciprocally, and may be responsible for regulating current amplitude.
Tadashi Kimura; Tai Kubo
Related Documents :
14682977 - Helix versus sheet formation in a small peptide.
8454467 - Posttranslational modification of beta 141 leu associated with the beta 75(e19)leu-->pr...
17193247 - Enzymatic degradation of beta- and mixed alpha,beta-oligopeptides.
19719157 - Synthesis of stapled beta3-peptides through ring-closing metathesis.
21687667 - Dinosaur peptides suggest mechanisms of protein survival.
19551937 - Assignment of disulfide-linked peptides using automatic a1 ion recognition.
Publication Detail:
Type:  Comparative Study; Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Neuroscience research     Volume:  46     ISSN:  0168-0102     ISO Abbreviation:  Neurosci. Res.     Publication Date:  2003 May 
Date Detail:
Created Date:  2003-05-02     Completed Date:  2003-07-08     Revised Date:  2009-11-19    
Medline Journal Info:
Nlm Unique ID:  8500749     Medline TA:  Neurosci Res     Country:  Ireland    
Other Details:
Languages:  eng     Pagination:  105-17     Citation Subset:  IM    
Molecular Neurophysiology Group, Neuroscience Research Institute, National Institute of Advanced Industrial Science and Technology, 1-1-1 Higashi, Tsukuba Central 6, Tsukuba, Ibaraki 305-8566, Japan.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Amino Acid Sequence
Calcium Channels / chemistry*,  genetics,  metabolism*
Casein Kinase II
Clone Cells
DNA, Complementary*
Decapodiformes / physiology*
Electric Stimulation
Membrane Potentials / physiology
Molecular Sequence Data
Oocytes / metabolism
Optic Lobe, Nonmammalian / physiology*
Protein Kinase C / metabolism
Protein Subunits
Protein-Serine-Threonine Kinases / metabolism
Reverse Transcriptase Polymerase Chain Reaction
Sequence Homology, Amino Acid
Xenopus laevis
Reg. No./Substance:
0/Calcium Channels; 0/DNA, Complementary; 0/Protein Subunits; EC Kinase II; EC Kinases; EC Kinase C

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Previous Document:  Resets of torsional eye position errors in different lighting conditions.
Next Document:  Protective effect of S-allyl-L-cysteine, a garlic compound, on amyloid beta-protein-induced cell dea...