dShab, Kv2
slow delayed rectifier K channel - upregulated by light stimulation - functions in light adaptation - regulates excitability in neurons and muscles, and transmitter release
Please see the GBrowse view of Dmel\Shab or the JBrowse view of Dmel\Shab for information on other features
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Gene model reviewed during 6.02
Contains low complexity sequences resulting in poly-glycine runs in the translation products.
Low-frequency RNA-Seq exon junction(s) not annotated.
Annotated transcripts do not represent all possible combinations of alternative exons and/or alternative promoters.
Annotated transcripts do not represent all supported alternative splices within 5' UTR.
Gene model reviewed during 5.46
6.8, 4.3 (northern blot)
955 (aa)
924 (aa)
100 (kD predicted)
The sequence of Shab in Canton-S contains an inserted base relative to Oregon-R leading to a frameshift and a C-terminal extension of the protein.
Co-injection experiments in Xenopus oocytes were used to test for formation of functional heterodimers between Sh subfamily members. In fact, no functional heterodimers (as shown by novel current kinetics) were detected when all pairwise combinations of the four different channel subfamilies (Sh, Shab, Shal, and Shaw) were tested. The independence of each channel system was retained even when all four were co-expressed.
Shab protein was expressed in Xenopus oocytes and characterized with respect to kinetics (rate of macroscopic current activation and inactivation) and voltage sensitivity of steady-state inactivation. Those properties were compared among the Sh subfamily members and found to vary widely. Shab encodes the transient (A current)subtype of potassium channel and appears to function as a homomultimer.
Heterotetramer of potassium channel proteins.
The N-terminus may be important in determining the rate of inactivation of the channel while the tail may play a role in modulation of channel activity and/or targeting of the channel to specific subcellular compartments.
Click to get a list of regulatory features (enhancers, TFBS, etc.) and gene disruptions (point mutations, indels, etc.) within or overlapping Dmel\Shab using the Feature Mapper tool.
GBrowse - Visual display of RNA-Seq signals
View Dmel\Shab in GBrowse 23-5
Please Note FlyBase no longer curates genomic clone accessions so this list may not be complete
Please Note This section lists cDNAs and ESTs that fall within the genomic extent of the gene model, which may include cDNAs and ESTs of genes within introns, or of overlapping genes. Please see GBrowse for alignment of the cDNAs and ESTs to the gene model.
For each fully sequenced cDNA the DGRC maintains various forms of the cDNA (e.g tagged or untagged) in several different host vectors for subsequent cloning and expression in Drosophila and Drosophila cell lines.
Source for identity of: Shab CG1066
Source for merge of: Shab CG9965
Annotations CG1066 and CG9965 merged as CG43128 in release 5.32 of the genome annotation.
The role of Shab channels in Drosophila photoreceptors is to dynamically attenuate the light-induced depolarisation and prevent response saturation in bright light.
A null mutation in Shab reduces the voltage-activated delayed sustained current (IK) but does not eliminate it. Observations suggest that IK consists of two components, which are genetically, pharmacalogically and physiologically distinct. These components are IKS (encoded by Shab) and IKF (which defines a new voltage-activated K+ current).
Shab may encode an 11 pS slowly inactivating K+ channel present in embryonic neurons.
Shab encodes the major delayed rectifier component of the K+ current in both embryonic muscles and neurons.
Yeast two-hybrid system studies demonstrate the association of the hydrophilic N-terminal domains of the genes encoding channel proteins plays an important role in determining the specificity of α subunit association to form heteromultimeric potassium channels.
Shab potassium channel and a mouse brain homolog potassium channel have similar kinetic, voltage sensitive and pharmacological properties. The greatest functional difference is recovery from inactivation.
Potassium channel diversity could result from an extended gene family as well as from alternate splicing of the Sh primary transcript.
