Gene splicing of an invertebrate beta subunit (LCavβ) in the N-terminal and HOOK domains and its regulation of LCav1 and LCav2 calcium channels.

The accessory beta subunit (Ca(v)β) of calcium channels first appear in the same genome as Ca(v)1 L-type calcium channels in single-celled coanoflagellates. The complexity of this relationship expanded in vertebrates to include four different possible Ca(v)β subunits (β1, β2, β3, β4) which associate...

Full description

Saved in:
Bibliographic Details
Main Authors: Taylor F Dawson, Adrienne N Boone, Adriano Senatore, Joshua Piticaru, Shano Thiyagalingam, Daniel Jackson, Angus Davison, J David Spafford
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2014-01-01
Series:PLoS ONE
Online Access:https://doi.org/10.1371/journal.pone.0092941
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1850125049373130752
author Taylor F Dawson
Adrienne N Boone
Adriano Senatore
Joshua Piticaru
Shano Thiyagalingam
Daniel Jackson
Angus Davison
J David Spafford
author_facet Taylor F Dawson
Adrienne N Boone
Adriano Senatore
Joshua Piticaru
Shano Thiyagalingam
Daniel Jackson
Angus Davison
J David Spafford
author_sort Taylor F Dawson
collection DOAJ
description The accessory beta subunit (Ca(v)β) of calcium channels first appear in the same genome as Ca(v)1 L-type calcium channels in single-celled coanoflagellates. The complexity of this relationship expanded in vertebrates to include four different possible Ca(v)β subunits (β1, β2, β3, β4) which associate with four Ca(v)1 channel isoforms (Ca(v)1.1 to Ca(v)1.4) and three Ca(v)2 channel isoforms (Ca(v)2.1 to Ca(v)2.3). Here we assess the fundamentally-shared features of the Ca(v)β subunit in an invertebrate model (pond snail Lymnaea stagnalis) that bears only three homologous genes: (LCa(v)1, LCa(v)2, and LCa(v)β). Invertebrate Ca(v)β subunits (in flatworms, snails, squid and honeybees) slow the inactivation kinetics of Ca(v)2 channels, and they do so with variable N-termini and lacking the canonical palmitoylation residues of the vertebrate β2a subunit. Alternative splicing of exon 7 of the HOOK domain is a primary determinant of a slow inactivation kinetics imparted by the invertebrate LCa(v)β subunit. LCa(v)β will also slow the inactivation kinetics of LCa(v)3 T-type channels, but this is likely not physiologically relevant in vivo. Variable N-termini have little influence on the voltage-dependent inactivation kinetics of differing invertebrate Ca(v)β subunits, but the expression pattern of N-terminal splice isoforms appears to be highly tissue specific. Molluscan LCa(v)β subunits have an N-terminal "A" isoform (coded by exons: 1a and 1b) that structurally resembles the muscle specific variant of vertebrate β1a subunit, and has a broad mRNA expression profile in brain, heart, muscle and glands. A more variable "B" N-terminus (exon 2) in the exon position of mammalian β3 and has a more brain-centric mRNA expression pattern. Lastly, we suggest that the facilitation of closed-state inactivation (e.g. observed in Ca(v)2.2 and Ca(v)β3 subunit combinations) is a specialization in vertebrates, because neither snail subunit (LCa(v)2 nor LCa(v)β) appears to be compatible with this observed property.
format Article
id doaj-art-d02de9208eea4b4eb0bda2df3b411f24
institution OA Journals
issn 1932-6203
language English
publishDate 2014-01-01
publisher Public Library of Science (PLoS)
record_format Article
series PLoS ONE
spelling doaj-art-d02de9208eea4b4eb0bda2df3b411f242025-08-20T02:34:10ZengPublic Library of Science (PLoS)PLoS ONE1932-62032014-01-0194e9294110.1371/journal.pone.0092941Gene splicing of an invertebrate beta subunit (LCavβ) in the N-terminal and HOOK domains and its regulation of LCav1 and LCav2 calcium channels.Taylor F DawsonAdrienne N BooneAdriano SenatoreJoshua PiticaruShano ThiyagalingamDaniel JacksonAngus DavisonJ David SpaffordThe accessory beta subunit (Ca(v)β) of calcium channels first appear in the same genome as Ca(v)1 L-type calcium channels in single-celled coanoflagellates. The complexity of this relationship expanded in vertebrates to include four different possible Ca(v)β subunits (β1, β2, β3, β4) which associate with four Ca(v)1 channel isoforms (Ca(v)1.1 to Ca(v)1.4) and three Ca(v)2 channel isoforms (Ca(v)2.1 to Ca(v)2.3). Here we assess the fundamentally-shared features of the Ca(v)β subunit in an invertebrate model (pond snail Lymnaea stagnalis) that bears only three homologous genes: (LCa(v)1, LCa(v)2, and LCa(v)β). Invertebrate Ca(v)β subunits (in flatworms, snails, squid and honeybees) slow the inactivation kinetics of Ca(v)2 channels, and they do so with variable N-termini and lacking the canonical palmitoylation residues of the vertebrate β2a subunit. Alternative splicing of exon 7 of the HOOK domain is a primary determinant of a slow inactivation kinetics imparted by the invertebrate LCa(v)β subunit. LCa(v)β will also slow the inactivation kinetics of LCa(v)3 T-type channels, but this is likely not physiologically relevant in vivo. Variable N-termini have little influence on the voltage-dependent inactivation kinetics of differing invertebrate Ca(v)β subunits, but the expression pattern of N-terminal splice isoforms appears to be highly tissue specific. Molluscan LCa(v)β subunits have an N-terminal "A" isoform (coded by exons: 1a and 1b) that structurally resembles the muscle specific variant of vertebrate β1a subunit, and has a broad mRNA expression profile in brain, heart, muscle and glands. A more variable "B" N-terminus (exon 2) in the exon position of mammalian β3 and has a more brain-centric mRNA expression pattern. Lastly, we suggest that the facilitation of closed-state inactivation (e.g. observed in Ca(v)2.2 and Ca(v)β3 subunit combinations) is a specialization in vertebrates, because neither snail subunit (LCa(v)2 nor LCa(v)β) appears to be compatible with this observed property.https://doi.org/10.1371/journal.pone.0092941
spellingShingle Taylor F Dawson
Adrienne N Boone
Adriano Senatore
Joshua Piticaru
Shano Thiyagalingam
Daniel Jackson
Angus Davison
J David Spafford
Gene splicing of an invertebrate beta subunit (LCavβ) in the N-terminal and HOOK domains and its regulation of LCav1 and LCav2 calcium channels.
PLoS ONE
title Gene splicing of an invertebrate beta subunit (LCavβ) in the N-terminal and HOOK domains and its regulation of LCav1 and LCav2 calcium channels.
title_full Gene splicing of an invertebrate beta subunit (LCavβ) in the N-terminal and HOOK domains and its regulation of LCav1 and LCav2 calcium channels.
title_fullStr Gene splicing of an invertebrate beta subunit (LCavβ) in the N-terminal and HOOK domains and its regulation of LCav1 and LCav2 calcium channels.
title_full_unstemmed Gene splicing of an invertebrate beta subunit (LCavβ) in the N-terminal and HOOK domains and its regulation of LCav1 and LCav2 calcium channels.
title_short Gene splicing of an invertebrate beta subunit (LCavβ) in the N-terminal and HOOK domains and its regulation of LCav1 and LCav2 calcium channels.
title_sort gene splicing of an invertebrate beta subunit lcavβ in the n terminal and hook domains and its regulation of lcav1 and lcav2 calcium channels
url https://doi.org/10.1371/journal.pone.0092941
work_keys_str_mv AT taylorfdawson genesplicingofaninvertebratebetasubunitlcavbinthenterminalandhookdomainsanditsregulationoflcav1andlcav2calciumchannels
AT adriennenboone genesplicingofaninvertebratebetasubunitlcavbinthenterminalandhookdomainsanditsregulationoflcav1andlcav2calciumchannels
AT adrianosenatore genesplicingofaninvertebratebetasubunitlcavbinthenterminalandhookdomainsanditsregulationoflcav1andlcav2calciumchannels
AT joshuapiticaru genesplicingofaninvertebratebetasubunitlcavbinthenterminalandhookdomainsanditsregulationoflcav1andlcav2calciumchannels
AT shanothiyagalingam genesplicingofaninvertebratebetasubunitlcavbinthenterminalandhookdomainsanditsregulationoflcav1andlcav2calciumchannels
AT danieljackson genesplicingofaninvertebratebetasubunitlcavbinthenterminalandhookdomainsanditsregulationoflcav1andlcav2calciumchannels
AT angusdavison genesplicingofaninvertebratebetasubunitlcavbinthenterminalandhookdomainsanditsregulationoflcav1andlcav2calciumchannels
AT jdavidspafford genesplicingofaninvertebratebetasubunitlcavbinthenterminalandhookdomainsanditsregulationoflcav1andlcav2calciumchannels