Cilia are important motile cell organelles of organisms including man. This study continues a comprehensive attack on the structure and function of cilia, centering on ultrastructural correlates of ciliary motion, including analysis of the mechanism of movement and its regulation. This approach has been influential in the development of the sliding microtubule model of ciliary motility, now widely accepted. Despite the success of this model, fundamental questions remain regarding the basic interaction responsible for sliding and the hierarchy of regulatory processes between the sliding event and actual ciliary beat. One major aim of this proposal is to strengthen the hypothesis that a unique cycle of dynein arm activity is responsible for microtubule sliding in motile cilia, and to specify the structural bases of this cycle further. The subunit structure of the arm will be studied using negative stain, freeze etch and rotary shadow electron microscopy. Structure will be correlated with polypeptide composition, location of microtubule attachment points and ATPase activity.
A second aims i s to use such structural information to probe possible cooperative and/or asynchronous arm activity in the axoneme. Asynchronous arm activity is embodied in several axonemal switching hypotheses relating sliding of specific microtubules to defined beat positions. These hypotheses will be tested by direct readout of arm configuration along single doublets and from doublet to doublet in cilia treated with various ATP analogs or arrested in specific stroke positions, for example after treatment with Ca2+ or calmodulin (CaM)-directed drugs. The possibility that CaM or CaM-binding proteins are part of the dynein arm in some cilia will be explored. This information should lead to further understanding of normal ciliary activity and of ciliary malfunction in respiratory disease.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL022560-11
Application #
3336960
Study Section
Cellular Biology and Physiology Subcommittee 1 (CBY)
Project Start
1977-09-01
Project End
1989-08-31
Budget Start
1987-09-01
Budget End
1988-08-31
Support Year
11
Fiscal Year
1987
Total Cost
Indirect Cost
Name
Albert Einstein College of Medicine
Department
Type
Schools of Medicine
DUNS #
009095365
City
Bronx
State
NY
Country
United States
Zip Code
10461
Holwill, M E; Satir, P (1990) A physical model of microtubule sliding in ciliary axonemes. Biophys J 58:905-17
Satir, P; Sleigh, M A (1990) The physiology of cilia and mucociliary interactions. Annu Rev Physiol 52:137-55
Hamasaki, T; Murtaugh, T J; Satir, B H et al. (1989) In vitro phosphorylation of Paramecium axonemes and permeabilized cells. Cell Motil Cytoskeleton 12:1-11
Satir, P; Matsuoka, T (1989) Splitting the ciliary axoneme: implications for a ""switch-point"" model of dynein arm activity in ciliary motion. Cell Motil Cytoskeleton 14:345-58
Satir, P (1989) The role of axonemal components in ciliary motility. Comp Biochem Physiol A Comp Physiol 94:351-7
Lieberman, S J; Wasco, W; MacLeod, J et al. (1988) Immunogold localization of the regulatory subunit of a type II cAMP-dependent protein kinase tightly associated with mammalian sperm flagella. J Cell Biol 107:1809-16
Lieberman, S J; Hamasaki, T; Satir, P (1988) Ultrastructure and motion analysis of permeabilized Paramecium capable of motility and regulation of motility. Cell Motil Cytoskeleton 9:73-84
Satir, P (1988) Dynein as a microtubule translocator in ciliary motility: current studies of arm structure and activity pattern. Cell Motil Cytoskeleton 10:263-70
Spungin, B; Avolio, J; Arden, S et al. (1987) Dynein arm attachment probed with a non-hydrolyzable ATP analog. Structural evidence for patterns of activity. J Mol Biol 197:671-7
Avolio, J; Glazzard, A N; Holwill, M E et al. (1986) Structures attached to doublet microtubules of cilia: computer modeling of thin-section and negative-stain stereo images. Proc Natl Acad Sci U S A 83:4804-8

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