scholarly journals Identification of shorter length lamin A protein in mouse ear cartilage tissue

2015 ◽  
Vol 20 (2) ◽  
Author(s):  
Ramamoorthy M. Kalidas ◽  
Subramanian Elaiya Raja ◽  
Sivasubramaniam Sudhakar

AbstractLamin A is an intermediate filament protein which is cleaved by the enzyme, FACE 1 at VTRSY↓L. The cleavage is the final step in the production of the mature lamin A protein. The mature lamin A protein localizes in the inner membrane of the nucleus. The mutation in the lamin A gene causes many diseases, including accelerated aging. It is known that the protein is not expressed in neuronal cells of the brain. Many splicing variants of the lamin A gene have been reported. In this study, the amino acid sequence VTRSY (a penta-peptide repeat) was found in three different sites of the C-terminal end of the lamin A protein, the protein expressed in cells of ear cartilage tissues is shorter than the protein expressed in cells of the skin tissues. Using two lamin A antibodies, it was found that the amino acid sequence between penta-peptide 2 and 3 is missing in lamin A protein that was expressed in the cells of mouse ear cartilage tissue, besides the RT-PCR data confirmed that the corresponding coding sequence between the penta repeat 2 and 3 is intact. Cleavage may occur at the penta-peptide (VTRSY) at site 3 in the lamin A tail of mouse ear cartilage.

2005 ◽  
Vol 168 (7) ◽  
pp. 1039-1051 ◽  
Author(s):  
Akira Honda ◽  
Omayma S. Al-Awar ◽  
Jesse C. Hay ◽  
Julie G. Donaldson

Arf and Rab family GTPases regulate membrane traffic in cells, yet little is known about how they are targeted to distinct organelles. To identify sequences in Arf-1 necessary for Golgi targeting, we examined the localization of chimeras between Arf-1 and Arf-6. Here, we identify a 16–amino acid sequence in Arf-1 that specifies Golgi targeting and contains a motif (MXXE) that is important for Arf-1 binding to membrin, an ER-Golgi SNARE protein. The MXXE motif is conserved in all Arfs known to localize to the Golgi and enables Arf-1 to localize to the early Golgi. Arf-1 lacking these 16 aa can still localize to the late Golgi where it displays a more rapid Golgi-cytosol cycle than wild-type Arf-1. These studies suggest that membrin recruits Arf-1 to the early Golgi and reveal distinct kinetic cycles for Arf-1 at early and late Golgi determined by different sets of Arf regulators and effectors.


1989 ◽  
Vol 261 (3) ◽  
pp. 1015-1022 ◽  
Author(s):  
L G Sparrow ◽  
C P Robinson ◽  
D T W McMahon ◽  
M R Rubira

Component 7c is one of the four homologous type II intermediate-filament proteins that, by association with the complementary type I proteins, form the microfibrils or intermediate filaments in wool. Component 7c was isolated as the S-carboxymethyl derivative from Merino wool and its amino acid sequence was determined by manual and automatic sequencing of peptides produced by chemical and enzymic cleavage reactions. It is an N-terminally blocked molecule of 491 residues and Mr (not including the blocking group) of 55,600; the nature of the blocking group has not been determined. The predicted secondary structure shows that component 7c conforms to the now accepted pattern for intermediate-filament proteins in having a central rod-like region of approximately 310 residues of coiled-coil alpha-helix flanked by non-helical N-and C-terminal regions. The central region is divided by three non-coiled-coil linking segments into four helical segments 1A, 1B, 2A and 2B. The N-and C-terminal non-helical segments are 109 and 71 residues respectively and are rich in cysteine. Details of procedures use in determining the sequence of component 7c have been deposited as a Supplementary Publication SUP 50152 (65 pages) at the British Library Document Supply Centre, Boston Spa, Wetherby, West Yorkshire LS23 7BQ, U.K., from whom copies can be obtained on the terms indicated in Biochem. J. (1989) 257,5. The information comprises: (1) details of chemical and enzymic methods used for cleavage of component 7c, peptides CN1, CN2 and CN3, and various other peptides, (2) details of the procedures used for the fractionation and purification of peptides from (1), including Figures showing the elution profiles from the chromatographic steps used, (3) details of methods used to determine the C-terminal sequence of peptide CN3, and (4) detailed evidence to justify a number of corrections to the previously published sequence.


1992 ◽  
Vol 282 (1) ◽  
pp. 291-297 ◽  
Author(s):  
L G Sparrow ◽  
C P Robinson ◽  
J Caine ◽  
D T W McMahon ◽  
P M Strike

Component 5 is one of the four type II intermediate-filament proteins found in the hard keratin wool. It was isolated as the S-carboxymethyl derivative from Merino wool and its amino acid sequence was determined by manual and automatic sequencing of peptides produced by chemical and enzymic cleavage. Component 5 is an N-terminally blocked molecule of 503 residues and Mr (not including the blocking group) of 56,600. The blocking group has not been identified. The amino acid sequence of component 5 shows 77% sequence identity with that of component 7c, another type II wool intermediate-filament protein [Sparrow, Robinson, McMahon & Rubira (1989) Biochem. J. 261, 1015-1022]. The sequence similarity extends from the N-termini of the two molecules to residue 459 (component 5 sequence); however, there is no recognizable sequence similarity in the remaining C-terminal 43 amino acid residues. Details of procedures used in determining the sequence of component 5 have been deposited as a Supplementary Publication SUP 50168 (80 pages) at the British Library Document Supply Centre, Boston Spa, Wetherby, West Yorkshire, LS23 7BQ, U.K., from whom copies can be obtained on the terms indicated in Biochem. J. (1992) 281, 5. The information comprises: (1) details of chemical and enzymic methods used for cleavage of component 5, peptide CN1, the peptide mixture CN2/3 and various other peptides, (2) details of the procedures used for the fractionation and purification of peptides from (1), including Figures showing the elution profiles from the chromatographic steps used, and (3) details of the method used to determine the C-terminal sequence of component 5.


1994 ◽  
Vol 127 (5) ◽  
pp. 1327-1343 ◽  
Author(s):  
M J Monteiro ◽  
C Hicks ◽  
L Gu ◽  
S Janicki

The mechanism by which nuclear and cytoplasmic filaments are sorted in vivo was studied by examining which lamin sequences are required to target an otherwise cytoplasmic IF protein, the small neurofilament subunit (NF-L), to the nuclear lamina. By swapping corresponding domains between NF-L and lamin A, nuclear envelope targeting of NF-L was shown to require the presence of the "head" domain, a 42-amino acid sequence unique to lamin rod domains, a nuclear localization signal and the CAAX motif. Replacement of the entire COOH-terminal tail of lamin A with that of NF-L had no discernible effect on nuclear localization of lamin A, provided the substituted NF-L tail contained a NLS and a CAAX motif. This chimeric protein exhibited characteristics more typical of lamin B than that of the parental lamin A. With regard to cytoplasmic assembly properties, substitution of the head domain of lamin A for that of NF-L did not substantially affect the ability of NF-L to coassemble with vimentin in the cytoplasm. In contrast, insertion of a 42-amino acid sequence unique to lamin rod domains into NF-L profoundly affected NF-L coassembly with vimentin indicating that the 42-amino acid insertion in lamins may be important for sorting lamins from cytoplasmic IF proteins.


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