TCDB is operated by the Saier Lab Bioinformatics Group
TCIDNameDomainKingdom/PhylumProtein(s)
*1.A.82.1.1









Mechanotransduction channel complex of cochlear hair cells TMHS/LHFPL5 is encoded by the Lhfpl5 gene.  The complex contains several proteins:  the tetraspan membrane protein of hair cell stereocilia, (TMHS protein) or Lipoma HMGIC fusion partner-like 5 protein (LHFPL5) (Fettiplace 2016), the Protocadherin-15 protein, PCDH15, and the Tmc1 and Tmc2 proteins (TC# 1.A.17) (Xiong et al. 2012).  TMHS and PCDH15 interact directly with Tmc1 and Tmc2, and these interactions are required for mechanotransduction (Maeda et al. 2014; Beurg et al. 2015). A primary function of Tmc1 may be calcium transport (Beurg et al. 2015).  Hair cells express two molecularly and functionally distinct mechanotransduction channels with different subcellular distributions. One is activated by sound and is responsible for sensory transduction. This sensory transduction channel is expressed in hair cell stereocilia, and its activity is affected by mutations in the genes encoding the transmembrane proteins TMHS (this family), TMIE (TC family 8.A.116), TMC1 and TMC2 (family 1.A.17.4) (Wu et al. 2016). Thus, these 4 proteins may all be parts of a single channel complex.  The other channel is the Piezo2 channel (TC# 1.A.75.1.2). TMHS is 68% identical to the human LHFPL3 protein (Q86UP9), and 62% identical to the human LHFPL4 protein (Q7Z7J7). The structure of protocadherin 15 with the tetraspan, LHFP5, has been determined (Ge et al. 2018).

Eukaryota
Metazoa
The mechanotransduction channel complex of Homo sapiens:
Tetraspan TMHS (Q8TAF8)
Protocadherin-15 (Q96QU1)
*1.A.82.1.2









Lipoma HMGIC fusion partner-like 2 protein of 220 aas and 4 TMSs.  The Human ortholog has UniProt acc # Q6ZUX7 with 228 aas and 85% identity with the mouse protein.

Eukaryota
Metazoa
Lipoma HMGIC fusion partner-like 2 protein of Mus musculus (Q8BGA2)
*1.A.82.1.3









Lipoma HMGIC fusion partner-like 2 protein, LHPL2

Eukaryota
Metazoa
LHPL2 of Lepeophtheirus salmonis (salmon louse)
*1.A.82.1.4









Hypothetical protein of 299 aas

Eukaryota
Metazoa
HP of Daphnia pulex
*1.A.82.1.5









Uncharacterized protein of 218 aas and 4 TMSs.

Eukaryota
Metazoa
UP of Capitella teleta (Polychaete worm)
*1.A.82.1.6









The Lipoma HMGIC fusion partner, LHFP of 200 aas and 4 TMSs. Acts as a translocation partner of HMGIC in a lipoma (Petit et al. 1999).

Eukaryota
Metazoa
LHFP of Homo sapiens
*1.A.82.1.7









Tetraspan protein LHFPL4 of 245 aas and 4 TMSs.  It is a synapse-specific tetraspanin essential for inhibitory synapse function because it promotes cell-type specific targeting and clustering of synaptic GABA recpetors (Davenport et al. 2017).

Eukaryota
Metazoa
LHFPL4 of Homo sapiens