Structure of the acrosomal bundle

Michael F. Schmid; Michael B. Sherman; Paul Matsudaira; Wah Chiu

doi:10.1038/nature02881

Structure of the acrosomal bundle

Michael F. Schmid, Michael B. Sherman, Paul Matsudaira, Wah Chiu

Research output: Contribution to journal › Letter › peer-review

71 Scopus citations

Abstract

In the unactivated Limulus sperm, a 60-μm-long bundle of actin filaments crosslinked by the protein scruin is bent and twisted into a coil around the base of the nucleus. At fertilization, the bundle uncoils and fully extends in five seconds to support a finger of membrane known as the acrosomal process. This biological spring is powered by stored elastic energy and does not require the action of motor proteins or actin polymerization. In a 9.5-Å electron cryomicroscopic structure of the extended bundle, we show that twist, tilt and rotation of actin-scruin subunits deviate widely from a ‘standard’ F-actin filament. This variability in structural organization allows filaments to pack into a highly ordered and rigid bundle in the extended state and suggests a mechanism for storing and releasing energy between coiled and extended states without disassembly.

Original language	English (US)
Pages (from-to)	104-107
Number of pages	4
Journal	Nature
Volume	431
Issue number	7004
DOIs	https://doi.org/10.1038/nature02881
State	Published - Sep 2 2004
Externally published	Yes

ASJC Scopus subject areas

General

Access to Document

10.1038/nature02881

Cite this

@article{60ad15e601184b87864103e68979373a,

title = "Structure of the acrosomal bundle",

abstract = "In the unactivated Limulus sperm, a 60-μm-long bundle of actin filaments crosslinked by the protein scruin is bent and twisted into a coil around the base of the nucleus. At fertilization, the bundle uncoils and fully extends in five seconds to support a finger of membrane known as the acrosomal process. This biological spring is powered by stored elastic energy and does not require the action of motor proteins or actin polymerization. In a 9.5-{\AA} electron cryomicroscopic structure of the extended bundle, we show that twist, tilt and rotation of actin-scruin subunits deviate widely from a {\textquoteleft}standard{\textquoteright} F-actin filament. This variability in structural organization allows filaments to pack into a highly ordered and rigid bundle in the extended state and suggests a mechanism for storing and releasing energy between coiled and extended states without disassembly.",

author = "Schmid, {Michael F.} and Sherman, {Michael B.} and Paul Matsudaira and Wah Chiu",

note = "Funding Information: Acknowledgements This research is supported by the NCRR and NIGMS of NIH. We thank M. Baker for assistance in the helixhunter and foldhunter searches, and M. Dougherty for advice on graphical display. Funding Information: Acknowledgements We thank T. Ideker and S. McCuine for help in selecting regulators to study in environmental conditions; E. Herbolsheimer, G. Bell, R. Latek and F. Lewitter for computational assistance; and E. McReynolds for technical assistance. E.F. is a Whitehead Fellow and was funded in part by Pfizer. D.B.G. was supported by a NIH/NIGMS NRSA award. This work was supported by an NIH grant.",

year = "2004",

month = sep,

day = "2",

doi = "10.1038/nature02881",

language = "English (US)",

volume = "431",

pages = "104--107",

journal = "Nature",

issn = "0028-0836",

publisher = "Nature Publishing Group",

number = "7004",

}

TY - JOUR

T1 - Structure of the acrosomal bundle

AU - Schmid, Michael F.

AU - Sherman, Michael B.

AU - Matsudaira, Paul

AU - Chiu, Wah

N1 - Funding Information: Acknowledgements This research is supported by the NCRR and NIGMS of NIH. We thank M. Baker for assistance in the helixhunter and foldhunter searches, and M. Dougherty for advice on graphical display. Funding Information: Acknowledgements We thank T. Ideker and S. McCuine for help in selecting regulators to study in environmental conditions; E. Herbolsheimer, G. Bell, R. Latek and F. Lewitter for computational assistance; and E. McReynolds for technical assistance. E.F. is a Whitehead Fellow and was funded in part by Pfizer. D.B.G. was supported by a NIH/NIGMS NRSA award. This work was supported by an NIH grant.

PY - 2004/9/2

Y1 - 2004/9/2

N2 - In the unactivated Limulus sperm, a 60-μm-long bundle of actin filaments crosslinked by the protein scruin is bent and twisted into a coil around the base of the nucleus. At fertilization, the bundle uncoils and fully extends in five seconds to support a finger of membrane known as the acrosomal process. This biological spring is powered by stored elastic energy and does not require the action of motor proteins or actin polymerization. In a 9.5-Å electron cryomicroscopic structure of the extended bundle, we show that twist, tilt and rotation of actin-scruin subunits deviate widely from a ‘standard’ F-actin filament. This variability in structural organization allows filaments to pack into a highly ordered and rigid bundle in the extended state and suggests a mechanism for storing and releasing energy between coiled and extended states without disassembly.

AB - In the unactivated Limulus sperm, a 60-μm-long bundle of actin filaments crosslinked by the protein scruin is bent and twisted into a coil around the base of the nucleus. At fertilization, the bundle uncoils and fully extends in five seconds to support a finger of membrane known as the acrosomal process. This biological spring is powered by stored elastic energy and does not require the action of motor proteins or actin polymerization. In a 9.5-Å electron cryomicroscopic structure of the extended bundle, we show that twist, tilt and rotation of actin-scruin subunits deviate widely from a ‘standard’ F-actin filament. This variability in structural organization allows filaments to pack into a highly ordered and rigid bundle in the extended state and suggests a mechanism for storing and releasing energy between coiled and extended states without disassembly.

UR - http://www.scopus.com/inward/record.url?scp=4544327988&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=4544327988&partnerID=8YFLogxK

U2 - 10.1038/nature02881

DO - 10.1038/nature02881

M3 - Letter

C2 - 15343340

AN - SCOPUS:4544327988

SN - 0028-0836

VL - 431

SP - 104

EP - 107

JO - Nature

JF - Nature

IS - 7004

ER -

Structure of the acrosomal bundle

Abstract

ASJC Scopus subject areas

Access to Document

Other files and links

Fingerprint

Cite this