Regulatory and essential light-chain-binding sites in myosin heavy chain subfragment-1 mapped by site-directed mutagenesis

Mitchell, E J; Karn, Jonathan; Brown, D. M.; Newman, Andrew; Jakes, Ross; Kendrick‐Jones, John

doi:10.1016/0022-2836(89)90096-x

Cited by 31 publications

(10 citation statements)

References 37 publications

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“…The myosins-II contain two such repeats, although the second repeat is poorly conserved in its latter half and it ends just ahead of the proline that defines the beginning of the myosin-II tail domain. Numerous studies (Mitchell et al, 1989;Nyitray et al, 1991) have implicated the ~100 amino acids in the myosin-II "neck" domain as providing the primary binding sites for the essential and regulatory myosin light chains. Moreover, a recent study has demonstrated that deletion of 16 amino acids from what we would define as the first IQ repeat in rat cardiac myosin eliminates binding to the essential myosin light chain (McNally et al, 1991).…”

Section: Neck Domain Of Chicken Myosin-v Hc Is Comprised Of Six Tandementioning

confidence: 99%

Primary structure and cellular localization of chicken brain myosin-V (p190), an unconventional myosin with calmodulin light chains.

Espreáfico

Cheney

Matteoli

et al. 1992

The Journal of Cell Biology

343

274

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Abstract. Recent biochemical studies of p190, a calmodulin (CM)-binding protein purified from vertebrate brain, have demonstrated that this protein, purified as a complex with bound CM, shares a number of properties with myosins (Espindola, E S., E. M. Esprearico, M. V. Coelho, A. R. Martins, E R. C. Costa, M. S. Mooseker, and R. E. Larson. 1992. J. Cell Biol. 118:359-368). To determine whether or not p190 was a member of the myosin family of proteins, a set of overlapping cDNAs encoding the full-length protein sequence of chicken brain p190 was isolated and sequenced. Verification that the deduced primary structure was that of p190 was demonstrated through microsequence analysis of a cyanogen bromide peptide generated from chick brain p190. The deduced primary structure of chicken brain p190 revealed that this 1,830-amino acid (aa) 212,509-D) protein is a member of a novel structural class of unconventional myosins that includes the gene products encoded by the dilute locus of mouse and the MYO2 gene of Saccharomyces cerevisiae. We have named the pl90-CM complex "myosin-V" based on the results of a detailed sequence comparison of the head domains of 29 myosin heavy chains (hc), which has revealed that this myosin, based on head structure, is the fifth of six distinct structural classes of myosin to be described thus far. Like the presumed products of the mouse dilute and yeast MYO2 genes, the head domain of chicken myosin-V hc (aa 1-764) is linked to a "neck" domain (aa 765-909) consisting of six tandem repeats of an ~23-aa "IQ-motify All known myosins contain at least one such motif at their head-tail junctions; these IQ-motifs may function as calmodulin or light chain binding sites. The tail domain of chicken myosin-V consists of an initial 511 aa predicted to form several segments of coiled-coil t~ helix followed by a terminal 410-aa globular domain (aa, 1,421-1,830). Interestingly, a portion of the tail domain (aa, 1,094-1,830) shares 58 % amino acid sequence identity with a 723-aa protein from mouse brain reported to be a glutamic acid decarboxylase. The neck region of chicken myosin-V, which contains the IQ-motifs, was demonstrated to contain the binding sites for CM by analyzing CM binding to bacterially expressed fusion proteins containing the head, neck, and tail domains. Immunolocalization of myosin-V in brain and in cultured cells revealed an unusual distribution for this myosin in both neurons and nonneuronal cells. Myosin-V staining was particularly intense in the cell bodies and dendrites of Purkinje cells. Double labeling with wheat germ agglutinin revealed colocalization of myosin-V with cytoplasmic, presumably Golgi-derived, membranes. In primary cultures of neurons and glia, myosin-V immunoreactivity had a punctate distribution more abundant in the region of the Golgi complex and at the tips of long processes such as growth cones. These results, together with the phenotypes of mutations described for the dilute and myo2 genes, suggest that the myosin-V family of unconventional myosins may be ...

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Section: Neck Domain Of Chicken Myosin-v Hc Is Comprised Of Six Tandementioning

confidence: 99%

Primary structure and cellular localization of chicken brain myosin-V (p190), an unconventional myosin with calmodulin light chains.

Espreáfico

Cheney

Matteoli

et al. 1992

The Journal of Cell Biology

343

274

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“…The corresponding subfragments of the human cardiac a-MHC were compared with the known amino acid sequences of the rod portion of nematode myosin [ McLachlan and Karn, 19821, of the S2 subfragment from the rabbit skeletal muscle MHC [Lu and Wong, 19853, of the rat embryonic skeletal muscle MHC [ Strehler et al, 19861 and of the rat cardiac aand 8-MHC [McNally et al, 19891, and were assigned as follows: MHC S1 residues 1 to 839; MHC short S2 residues 840 to 1128; S2 hinge residues 1129 to 1281; MHC light meromyosin (LMM) residues 1282 to 1939 [Fry et al, 1986;Tong and Elzinga, 1983;Walker et al, 19823, actin [Chaussepied et al, 1988;1986;Sutoh, 1982;Mornet et al, 1981 3 and myosin light chain [Mitchell et al, 1989;19861. Amino acid sequence comparison of the human cardiac a-MHC with the 2 reported human cardiac 6-MHC [Jaenicke et al, 1990;Liew et al, 19901 has demonstrated that there are, at least, 7 isoform-specific divergent regions (which are underlined in Fig.…”

Section: Amino Acid Sequence Characteristics Of Human Cardiac A-mhc Genementioning

confidence: 99%

Complete sequence of human cardiac α‐myosin heavy chain gene and amino acid comparison to other myosins based on structural and functional differences

et al. 1991

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We have obtained the 5820 nucleotide sequence encoding all 1939 amino acids of the human cardiac alpha-myosin heavy chain (alpha-MHC), as established by dideoxy sequencing of cloned cDNA, genomic DNA and polymerase chain reaction (PCR) amplification products. This sequence represents overlapping fragments of the entire coding sequence. Amino acid sequence comparison of the human cardiac alpha-MHC with the published human cardiac beta-MHC have demonstrated that there are, at least, 7 isoform-specific divergent regions, including functionally important binding protein-related sites such as ATP, actin and myosin light chain. It has been reported that in the rat, there are 8 isoform-specific divergent regions. The 7th divergent area (residue area 1633-1657, which is thought to mediate thick filament formation) in the light meromyosin region in the rat is not apparent in the human. The amino acid compositions of cardiac alpha- and beta-MHCs in the human and the rat, and human embryonic skeletal muscle and chicken gizzard smooth muscles were compared. Amino acid sequences in cardiac alpha- and beta-MHCs in the human and the rat are well conserved. In the head portion, the amino acid composition divergence of human cardiac alpha-MHC is ranked between rat cardiac alpha-MHC and human cardiac beta- or rat cardiac beta-MHC; human skeletal muscle MHC is the most divergent of the myosin isoform examined. These data predict that human cardiac alpha-MHC may have undergone evolutionary changes toward obtaining the biochemical and physiological properties of cardiac beta-MHC.

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“…The nature of the Ca 2+ ‐independent binding sites responsible for CaM recognition has been elucidated primarily by studies of the interaction of the myosin light chains with conventional, class II myosin in conjunction with sequence analysis of unconventional myosins [15–17]. The two light‐chain‐binding regions of the conventional myosin neck region are highly specific.…”

Section: Introductionmentioning

confidence: 99%

Calmodulin signaling via the IQ motif

2001

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The IQ motif is widely distributed in both myosins and non-myosins and is quite common in the database that includes more than 900 Pfam entries. An examination of IQ motif-containing proteins that are known to bind calmodulin (CaM) indicates a wide diversity of biological functions that parallel the Ca 2+ -dependent targets. These proteins include a variety of neuronal growth proteins, myosins, voltage-operated channels, phosphatases, Ras exchange proteins, sperm surface proteins, a Ras Gap-like protein, spindle-associated proteins and several proteins in plants. The IQ motif occurs in some proteins with Ca 2+ -dependent CaM interaction where it may promote Ca 2+ -independent retention of CaM. The action of the IQ motif may result in complex signaling as observed for myosins and the L-type Ca 2+ channels and is highly localized as required for sites of neuronal polarized growth and plasticity, fertilization, mitosis and cytoskeletal organization. The IQ motif associated with the unconventional myosins also promotes Ca 2+ regulation of the vectorial movement of cellular constituents to these sites. Additional regulatory roles for this versatile motif seem likely. ß

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Regulatory and essential light-chain-binding sites in myosin heavy chain subfragment-1 mapped by site-directed mutagenesis

Cited by 31 publications

References 37 publications

Primary structure and cellular localization of chicken brain myosin-V (p190), an unconventional myosin with calmodulin light chains.

Primary structure and cellular localization of chicken brain myosin-V (p190), an unconventional myosin with calmodulin light chains.

Complete sequence of human cardiac α‐myosin heavy chain gene and amino acid comparison to other myosins based on structural and functional differences

Calmodulin signaling via the IQ motif

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