A novel myosin I from bovine adrenal gland

Zhu, Tao; Ikebe, Mitsuo

doi:10.1016/0014-5793(94)80378-1

Cited by 16 publications

(18 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…At the resolution of the investigation, there are no detectable conformational changes in the motor domain between the ADP and nucleotide‐free states. Distal to the motor domain, elongated density attributable to the three calmodulins of the light chain binding domain (LCBD) (Reizes et al , 1994; Zhu and Ikebe, 1994; Ruppert et al , 1995) is visualised in both states. In the nucleotide‐free state (red, Figure 2), the LCBD projects outwards from the end of the motor domain.…”

Section: Resultsmentioning

confidence: 99%

Myo1c is designed for the adaptation response in the inner ear

Batters¹,

Arthur

Lin

et al. 2004

EMBO J

111

View full text Add to dashboard Cite

The molecular motor, Myo1c, a member of the myosin family, is widely expressed in vertebrate tissues. Its presence at strategic places in the stereocilia of the hair cells in the inner ear and studies using transgenic mice expressing a mutant Myo1c that can be selectively inhibited implicate it as the mediator of slow adaptation of mechanoelectrical transduction, which is required for balance. Here, we have studied the structural, mechanical and biochemical properties of Myo1c to gain an insight into how this molecular motor works. Our results support a model in which Myo1c possesses a strain-sensing ADPrelease mechanism, which allows it to adapt to mechanical load.

show abstract

Section: Resultsmentioning

confidence: 99%

Myo1c is designed for the adaptation response in the inner ear

Batters¹,

Arthur

Lin

et al. 2004

EMBO J

111

View full text Add to dashboard Cite

show abstract

“…It should be noted, however, Ca 2ϩ binding to calmodulin dissociates only one of the three bound calmodulin from myosin I␤ heavy chain. According to the amino acid sequence, myosin I␤ has three IQ motifs, one of which is not a completely matched IQ motif, IQXXXRGXXXR (one-letter amino acid code; X is any amino acid residue) (6). It is plausible that the calmodulin bound to the incomplete IQ motif is dissociated from myosin I␤ when Ca 2ϩ binds to the C-terminal domain.…”

Section: Discussionmentioning

confidence: 99%

“…tissues with the highest expression levels in heart, lung, adrenal gland, esophagus, and stomach (6,7,9,10). Myosin I␤ localizes to actin-rich peripheral structures, such as filopodia and lamellipodia of culture cells (9), and it is thought to play a role in cytoskeleton rearrangement.…”

mentioning

confidence: 99%

High Affinity Ca2+ Binding Sites of Calmodulin Are Critical for the Regulation of Myosin Iβ Motor Function

Zhu

Beckingham²,

Ikebe

1998

Journal of Biological Chemistry

Self Cite

View full text Add to dashboard Cite

We coexpressed myosin I␤ heavy chain with three different calmodulin mutants in which the two Ca 2؉ -binding sites of the two N-terminal domain (E12Q), C-terminal domain (E34Q), or all four sites (E1234Q) are mutated in order to define the importance of these Ca 2؉ binding sites to the regulation of myosin I␤. The calmodulin mutated at the two Ca 2؉ binding sites in N-terminal domain and C-terminal domain lost its lower affinity Ca 2؉ binding site and higher affinity Ca 2؉ binding site, respectively. We found that, based upon the change in the actin-activated ATPase activities and actin translocating activities, myosin I␤ with E12Q calmodulin has the regulatory characteristics similar to myosin I␤ containing wild-type calmodulin, while myosin I␤ with E34Q or E1234Q calmodulin lose all Ca 2؉ regulation. While the increase in myosin I␤ ATPase activity paralleled the dissociation of 1 mol of calmodulin from myosin I␤ heavy chain for both wild type (above pCa 5) and E12Q calmodulin (above pCa 6), the Ca 2؉ level required for the inhibition of actin-translocating activity of myosin I␤ was lower than that required for dissociation of calmodulin, suggesting that the conformational change induced by the binding of Ca 2؉ at the high affinity site but not the dissociation of calmodulin is critical for the inhibition of the motor activity. Our results suggest that the regulation of unconventional myosins by Ca 2؉ is directly mediated by the Ca 2؉ binding to calmodulin, and that the C-terminal pair of Ca 2؉ -binding sites are critical for this regulation.

show abstract

“…Myo1c is another class I myosin identified from various sources [70,[75][76][77][78]. It has three calmodulin (light chain)-binding sites and is bound by two to three calmodulins in the absence of Ca 2+ [79].…”

Section: Myo1c (Myosin Ib Myr 2)mentioning

confidence: 99%

Myosin I: From yeast to human

Kim

Flavell

2008

Cell. Mol. Life Sci.

View full text Add to dashboard Cite

Myosin I is a non-filamentous, single-headed, actin-binding motor protein and is present in a wide range of species from yeast to man. The role of these class I myosins have been studied extensively in simple eukaryotes, showing their role in diverse processes such as actin cytoskeleton organization, cell motility, and endocytosis. Recently, studies in metazoans have begun to reveal more specialized functions of myosin I. It will be a major challenge in the future to examine the physiological functions of each class I myosin in different cell types of metazoans.

show abstract

A novel myosin I from bovine adrenal gland

Cited by 16 publications

References 22 publications

Myo1c is designed for the adaptation response in the inner ear

Myo1c is designed for the adaptation response in the inner ear

High Affinity Ca2+ Binding Sites of Calmodulin Are Critical for the Regulation of Myosin Iβ Motor Function

Myosin I: From yeast to human

Contact Info

Product

Resources

About