Dephosphorylation of inner arm 1 is associated with ciliary reversals in <i>Tetrahymena thermophila</i>

Deckman, Cassandra M.; Pennock, David G.

doi:10.1002/cm.10158

Cited by 4 publications

(7 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For example, not only is I1-dynein activity regulated by phosphorylation in Chlamydomonas, recent data suggests that I1 activity plays a role in regulating motility in Tetrahymena thermophila [Hennessey et al, 2002;Deckman and Pennock, 2004].…”

Section: Introduction and Overviewmentioning

confidence: 99%

Keeping an eye on I1: I1 dynein as a model for flagellar dynein assembly and regulation

Wirschell

Hendrickson

Sale

2007

Cell Motil. Cytoskeleton

109

View full text Add to dashboard Cite

Among the major challenges in understanding ciliary and flagellar motility is to determine how the dynein motors are assembled and localized and how dyneindriven outer doublet microtubule sliding is controlled. Diverse studies, particularly in Chlamydomonas, have determined that the inner arm dynein I1 is targeted to a unique structural position and is critical for regulating the microtubule sliding required for normal ciliary/flagellar bending. As described in this review, I1 dynein offers additional opportunities to determine the principles of assembly and targeting of dyneins to cellular locations and for studying the mechanisms that regulate dynein activity and control of motility by phosphorylation. Cell Motil.

show abstract

Section: Introduction and Overviewmentioning

confidence: 99%

Keeping an eye on I1: I1 dynein as a model for flagellar dynein assembly and regulation

Wirschell

Hendrickson

Sale

2007

Cell Motil. Cytoskeleton

109

View full text Add to dashboard Cite

show abstract

“…Hypothetically pH changes could have direct effects on the outer dynein arm or influence the activity of axonemal kinases and phosphatases that are sensitive to pH (Cox & Taylor, 1995; Reddy et al 1998). Of particular interest is the cAMP‐dependent protein kinase (PKA), an important regulator of mammalian CBF (Wyatt et al 1998; Lieb et al 2002; Zagoory et al 2002), and phosphatases shown to control ciliary beating in protozoa (Klumpp et al 1990; Momayezi et al 1996; Noguchi et al 2003; Deckman & Pennock, 2004). Another important regulator of CBF, [Ca 2+ ] i , was also found to be regulated by pH i in several cell types (Thomas et al 1979; Browning & Wilkins, 2002).…”

mentioning

confidence: 99%

Regulation of human airway ciliary beat frequency by intracellular pH

Sutto¹,

Conner²,

Salathé³

2004

The Journal of Physiology

View full text Add to dashboard Cite

pH i affects a number of cellular functions, but the influence of pH i on mammalian ciliary beat frequency (CBF) is not known. CBF and pH i of single human tracheobronchial epithelial cells in submerged culture were measured simultaneously using video microscopy (for CBF) and epifluorescence microscopy with the pH-sensitive dye BCECF. Baseline CBF and pH i values in bicarbonate-free medium were 7.2 ± 0.2 Hz and 7.49 ± 0.02, respectively (n = 63). Alkalization by ammonium pre-pulse to pH i 7.78 ± 0.02 resulted in a 2.2 ± 0.1 Hz CBF increase (P < 0.05). Following removal of NH 4 Cl, pH i decreased to 7.24 ± 0.02 and CBF to 5.8 ± 0.1 Hz (P < 0.05). Removal of extracellular CO 2 to change pH i resulted in similar CBF changes. Pre-activation of cAMP-dependent protein kinase (10 µM forskolin), broad inhibition of protein kinases (100 µM H-7), inhibition of PKA (10 µM H-89), nor inhibition of phosphatases (10 µM cyclosporin + 1.5 µM okadaic acid) changed pH i -mediated changes in CBF, nor were they due to [Ca 2+ ] i changes. CBF of basolaterally permeabilized human tracheobronchial cells, re-differentiated at the air-liquid interface, was 3.9 ± 0.3, 5.7 ± 0.4, 7.0 ± 0.3 and 7.3 ± 0.3 Hz at basolateral i.e., intracellular pH of 6.8, 7.2, 7.6 and 8.0, respectively (n = 18). Thus, intracellular alkalization stimulates, while intracellular acidification attenuates human airway CBF. Since phosphorylation and [Ca 2+ ] i changes did not seem to mediate pH i -induced CBF changes, pH i may directly act on the ciliary motile machinery.

show abstract

Section: Discussionmentioning

confidence: 99%

“…A 112 kDa IC of I1 dynein is phosphorylated during forward swimming and dephosphorylated under depolarizing conditions that cause the ciliary reversal and backward swimming in Tetrahymena [Deckman and Pennock, 2004]. Inhibition of protein phosphatase 2A (PP2A) with cantharidin inhibits backward swimming in living cells and extracted cell models [Deckman and Pennock, 2004]. These observations suggest that the depolarization-induced Ca 2þ influx directly or indirectly activates PP2A to dephosphorylate the 112 kDa IC, which in turn, changes the activity of I1 IAD and leads to reversal of ciliary beating orientation.…”

Section: Discussionmentioning

confidence: 99%

“…However, we recently showed that a Tetrahymena mutant missing I1 cannot swim backward or undergo an AR, which indicated that I1 is essential for ciliary reversal [Hennessey et al, 2002]. We also demonstrated that in Tetrahymena a 112 kDa intermediate chain of I1 IAD is phosphorylated during forward swimming and dephosphorylated under conditions that cause ciliary reversal and that ciliary reversal in both live cells and permeabilized cell models is inhibited by phosphatase inhibitors [Deckman and Pennock, 2004]. These results suggest a model in which the phosphorylation state of I1 may regulate orientation of ciliary beating.…”

Section: Introductionmentioning

confidence: 90%

See 1 more Smart Citation

Mutations in genes encoding inner arm dynein heavy chains inTetrahymena thermophila lead to axonemal hypersensitivity to Ca2+

Liu

Hennessey

Rankin

et al. 2005

Cell Motil. Cytoskeleton

Self Cite

View full text Add to dashboard Cite

Calcium-dependent ciliary reversals are seen in ciliated protozoans such as Tetrahymena in response to depolarizing stimuli, but the axonemal mechanisms responsible for this response are not well understood. The model is that the outer arm dyneins (OADs) control the beating frequency while the inner arm dyneins (IADs) regulate ciliary waveform. Since ciliary reversal is a type of waveform change, the model would predict that IAD mutations could affect ciliary reversal. We have used gene disruption techniques to generate several behavioral mutants of Tetrahymena with functional disruptions of various IADs. One such mutant, called KO-6, is missing I1 (the two-headed IAD) and is unable to show ciliary reversals in response to any stimuli due to a loss of axonemal Ca2+ sensitivity [Eur J Cell Biol 80 (2001) 486-497; Cell Motil Cytoskeleton 53 (2002) 281-288.]. In contrast, disruption of 3 one-headed IADs [Liu et al., Cell Motil Cytoskeleton 59 (2004), 201-214] produced mutants, which showed over-responsiveness in bioassays measuring either their depolarization-induced avoiding reactions (AR) in Na+ and Ba2+ solutions or their duration of backward swimming (continuous ciliary reversal or CCR) in K+ solutions. Detergent-extracted and reactivated mutants also showed increased probabilities of CCR at lower Ca2+ concentrations suggesting that the behavioral over-responsiveness of these three mutants in vivo is due to increased axonemal Ca2+ sensitivity. Our data suggest the possibility that the one-headed IADs and the two-headed IAD act antagonistically in vivo and that loss of any one of the one-headed IADs leads to behavioral over-responsiveness due to less resistance to I1-induced reversals.

show abstract

Dephosphorylation of inner arm 1 is associated with ciliary reversals in Tetrahymena thermophila

Cited by 4 publications

References 40 publications

Keeping an eye on I1: I1 dynein as a model for flagellar dynein assembly and regulation

Keeping an eye on I1: I1 dynein as a model for flagellar dynein assembly and regulation

Regulation of human airway ciliary beat frequency by intracellular pH

Mutations in genes encoding inner arm dynein heavy chains inTetrahymena thermophila lead to axonemal hypersensitivity to Ca2+

Contact Info

Product

Resources

About