Localization of the Phosphoinositide effector protein SWAP70 (Switching B Cell Complex Subunit SWAP70) in the mouse cochlea

The phospholipid membrane of cells consists of a variety of different proteins that are critical for the function of the respective cell type. Phosphoinositides (PIs) are components of all cells and act as signalling molecules to affect together with its effector proteins a variety of processes like endo – and exocytosis, regulating the activity of ion – channels & – transporters, signal transduction and cytoskeletal dynamics. Transcriptome data suggest an expression of the PI dependent guanine nucleotide exchange factor (GEF) SWAP70 in the inner ear of the mouse, but the localization and function of SWAP70 in the inner ear remains elusive.

In this study, we analyse immunohistochemical stainings of whole-mount preparations from the mouse inner ear using confocal microscopy. The data reveal a pairwise-like expression pattern of SWAP70 at the phalangeal processes (PP) of several classes of supporting cells, including Deiter’s cells and inner & outer pillar cells. This expression pattern shows similarities to the centriole pair of the centrosome and co-localizes with the intraflagellar transport complex-A (IFT-A) core subunit IFT-140, which was shown to be present at the basal body (BB) of cilia in different cell lines and tissues.

This suggests that SWAP70 is probably localized to the centriole pair of supporting cells in the mouse inner ear. Based on these results the exact function of SWAP70 in the inner ear and its PI-dependency will be featured in following experiments using an established SWAP70<sup>-/-</sup > KO mouse-line.

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Artikel online veröffentlicht:
24. Mai 2022