8.A.231. The Quiver/Sleepless//Dreammist (QSD) Family QUIVER/SLEEPLESS/DREAMMIST orthologues in vaious animals are responsible for interactions with shaker-type potassium channels and nicotinic acetylcholine receptors (Wu et al. 2016). It suppress excitability and synaptic transmission by upregulating potassium (K⁺) channels and downregulating nicotinic acetylcholine receptors (nAChRs) in wake-promoting neurons to facilitate sleep in Drosophila (Wu et al. 2016). Furthermore, the zebrafish mutant dreammist implicates sodium homeostasis in sleep regulation (Barlow et al. 2023). Dreammist (dmist), the loss of which results in behavioural hyperactivity and reduced sleep at night, is encoded by a gene that is neuronally expressed (the dmist gene) and is conserved across vertebrates. It encodes a small single- or double-pass transmembrane protein that is structurally similar to the Na⁺,K⁺-ATPase regulator, FXYD1/Phospholemman. Disruption of either fxyd1 or atp1a3a, a Na⁺,K⁺-ATPase alpha-3 subunit associated with several heritable movement disorders in humans, led to decreased night-time sleep. Since atpa1a3a and dmist mutants have elevated intracellular Na⁺ levels and non-additive effects on sleep amount at night, Barlow et al. 2023 proposed that Dmist-dependent enhancement of Na⁺ pump function modulates neuronal excitability to maintain normal sleep behaviour. There are two subfamilies, 1 and 2; they are of different lengths but the same topologies with two TMSs and the N-and C-termini. However, membes of the two families do not bring each other up using TC BLAST. Their common origin is not established.
References:
Barlow, I.L., E. Mackay, E. Wheater, A. Goel, S. Lim, S. Zimmerman, I. Woods, D.A. Prober, and J. Rihel. (2023). The zebrafish mutant implicates sodium homeostasis in sleep regulation. Elife 12:.
Wu, M., C.Z. Liu, and W.J. Joiner. (2016). Structural Analysis and Deletion Mutagenesis Define Regions of QUIVER/SLEEPLESS that Are Responsible for Interactions with Shaker-Type Potassium Channels and Nicotinic Acetylcholine Receptors. PLoS One 11: e0148215.
Examples:
TC#	Name	Organismal Type	Example
8.A.231.1.1	Sleepless of 78 aas and 2 TMSs.		Sleepless of Homo sapiens

8.A.231.1.2	Uncharacterized protein of 72 aas and 2 TMSs, N- and C-terminal.		*UP of Synaphobranchus kaupii* (Kaup's arrowtooth eel)**

8.A.231.1.3	Uncharacterized protein of 72 aas and 2 TMSs, N- and C-terminal.		*UP of Solea senegalensis* (Senegalese sole)**

Examples:
TC#	Name	Organismal Type	Example
8.A.231.2.1	Quiver (Qvr) or Sleepless (Sss) of 158 aas and 2 TMSs, N- and C-terminal.		Qvr of Drosophila melanogaster

8.A.231.2.2	Uncharacterized protein of 167 aas and 2 TMSs, N- and C-terminal.		UP of Didymodactylos carnosus

8.A.231.2.3	Protein quiver-like isoform, X3, Qvr, of 159 aas and 2 TMSs, N- and C-terminal.		Qvr of Mya arenaria

8.A.231.2.4	Uncharacterized protein of 165 aas and 2 TMSs, N- and C-terminal		UP of Monomorium pharaonis

8.A.231.2.5	Uncharacterized protein of 160 aas and 2 TMSs, N- and C-terminal.		UP of Ancylostoma ceylanicum

8.A.231.2.6	Uncharacterized protein of 172 aas and 2 TMSs, N- and C-termnal.		UP of Ramazzottius varieornatus