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Absence of plastin 1 causes abnormal maintenance of hair cell stereocilia and a moderate form of hearing loss in mice.

Taylor R, Bullen A, Johnson SL, Grimm-Günter EM, Rivero F, Marcotti W, Forge A, Daudet N - Hum. Mol. Genet. (2014)

Bottom Line: Several actin-associated proteins are essential for stereocilia formation and maintenance, and their absence leads to deafness.Auditory hair cells developed normally in Pls1 KO, but in young adult animals, the stereocilia of inner hair cells were reduced in width and length.These results show that in contrast to other actin-bundling proteins such as espin, harmonin or Eps8, plastin 1 is dispensable for the initial formation of stereocilia.

View Article: PubMed Central - PubMed

Affiliation: Centre for Auditory Research, UCL Ear Institute, University College London, London, UK.

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Related in: MedlinePlus

Current and voltage responses from IHCs of plastin 1 mice. (A and B) K+ currents recorded from mature het and Pls1 KO P24 IHCs were elicited by depolarizing voltage steps (10-mV nominal increments) from –144 mV to more depolarized values from the holding potential of –64 mV. The K+ currents characteristic of adult IHCs, IK,f and IK,n were similarly expressed in both genotypes. (C) Steady-state current–voltage curves for the total K+ current in het (n = 5) and Pls1 KO (n = 5) P24 IHCs. (D and E) Voltage responses to different current injections recorded from a het and a Pls1 KO IHC.
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DDU417F7: Current and voltage responses from IHCs of plastin 1 mice. (A and B) K+ currents recorded from mature het and Pls1 KO P24 IHCs were elicited by depolarizing voltage steps (10-mV nominal increments) from –144 mV to more depolarized values from the holding potential of –64 mV. The K+ currents characteristic of adult IHCs, IK,f and IK,n were similarly expressed in both genotypes. (C) Steady-state current–voltage curves for the total K+ current in het (n = 5) and Pls1 KO (n = 5) P24 IHCs. (D and E) Voltage responses to different current injections recorded from a het and a Pls1 KO IHC.

Mentions: We next asked whether mature (P24) IHCs from Pls1 KO mice had normal biophysical properties, such as a rapidly activating large conductance Ca2+-activated K+ current (IK,f) and a current carried by KCNQ4 channels (IK,n) with an unusually hyperpolarized activation range (25). Depolarizing and hyperpolarizing voltage steps from the holding potential of −64 mV elicited similar voltage-dependent outward K+ currents in all IHCs tested from het and Pls1 KO mice (Fig. 7A–C). IK,f and IK,n were expressed with a similar amplitude in IHCs from both genotypes (Table 2). Voltage responses as well as all other biophysical properties (Table 2) were also similar between het and Pls1 KO IHCs (Fig. 7D and E), indicating that the absence of plastin 1 has no impact on the overall acquisition of the biophysical characteristics of IHCs.Table 2.


Absence of plastin 1 causes abnormal maintenance of hair cell stereocilia and a moderate form of hearing loss in mice.

Taylor R, Bullen A, Johnson SL, Grimm-Günter EM, Rivero F, Marcotti W, Forge A, Daudet N - Hum. Mol. Genet. (2014)

Current and voltage responses from IHCs of plastin 1 mice. (A and B) K+ currents recorded from mature het and Pls1 KO P24 IHCs were elicited by depolarizing voltage steps (10-mV nominal increments) from –144 mV to more depolarized values from the holding potential of –64 mV. The K+ currents characteristic of adult IHCs, IK,f and IK,n were similarly expressed in both genotypes. (C) Steady-state current–voltage curves for the total K+ current in het (n = 5) and Pls1 KO (n = 5) P24 IHCs. (D and E) Voltage responses to different current injections recorded from a het and a Pls1 KO IHC.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4262491&req=5

DDU417F7: Current and voltage responses from IHCs of plastin 1 mice. (A and B) K+ currents recorded from mature het and Pls1 KO P24 IHCs were elicited by depolarizing voltage steps (10-mV nominal increments) from –144 mV to more depolarized values from the holding potential of –64 mV. The K+ currents characteristic of adult IHCs, IK,f and IK,n were similarly expressed in both genotypes. (C) Steady-state current–voltage curves for the total K+ current in het (n = 5) and Pls1 KO (n = 5) P24 IHCs. (D and E) Voltage responses to different current injections recorded from a het and a Pls1 KO IHC.
Mentions: We next asked whether mature (P24) IHCs from Pls1 KO mice had normal biophysical properties, such as a rapidly activating large conductance Ca2+-activated K+ current (IK,f) and a current carried by KCNQ4 channels (IK,n) with an unusually hyperpolarized activation range (25). Depolarizing and hyperpolarizing voltage steps from the holding potential of −64 mV elicited similar voltage-dependent outward K+ currents in all IHCs tested from het and Pls1 KO mice (Fig. 7A–C). IK,f and IK,n were expressed with a similar amplitude in IHCs from both genotypes (Table 2). Voltage responses as well as all other biophysical properties (Table 2) were also similar between het and Pls1 KO IHCs (Fig. 7D and E), indicating that the absence of plastin 1 has no impact on the overall acquisition of the biophysical characteristics of IHCs.Table 2.

Bottom Line: Several actin-associated proteins are essential for stereocilia formation and maintenance, and their absence leads to deafness.Auditory hair cells developed normally in Pls1 KO, but in young adult animals, the stereocilia of inner hair cells were reduced in width and length.These results show that in contrast to other actin-bundling proteins such as espin, harmonin or Eps8, plastin 1 is dispensable for the initial formation of stereocilia.

View Article: PubMed Central - PubMed

Affiliation: Centre for Auditory Research, UCL Ear Institute, University College London, London, UK.

Show MeSH
Related in: MedlinePlus