scholarly journals Myosin from pancreatic acinar carcinoma cells. Isolation, characterization and demonstration of heavy- and light-chain phosphorylation

1987 ◽  
Vol 247 (3) ◽  
pp. 513-518 ◽  
Author(s):  
T K Watanabe ◽  
E R Kuczmarski ◽  
J K Reddy
Keyword(s):  
Ionic Strength ◽  
Atpase Activity ◽  
Heavy Chain ◽  
Electron Microscopic Examination ◽  
Acinar Cell Carcinoma ◽  
Pancreatic Acinar Cell ◽  
Pancreatic Acinar Cells ◽  
Light Chains ◽  
Post Translational Modification ◽  
Electron Microscopic

Myosin has been identified in a variety of non-muscle cells, and is believed to play a role in maintenance of cell shape, locomotion, cytokinesis, exocytosis and other cellular functions. In this paper we describe the purification of myosin from a pancreatic acinar-cell carcinoma of the rat which forms solid tumours, but retains many differentiated functions. The purified myosin was composed of a 200,000 Da heavy chain and two or three classes of light chains. Electron-microscopic examination of rotary-shadowed preparations revealed that individual molecules had two globular heads and a long tail measuring approx. 149 nm. The myosin was soluble in high-salt buffers and became sedimentable as the ionic strength was lowered. Examination of negative-stained preparations showed that this sedimentable myosin consisted of short, bipolar, thick filaments which had a strong tendency to aggregate in a head-to-head manner. The ATPase activity of the purified myosin was stimulated by EDTA or Ca2+, but not by Mg2+. In low ionic strength the Mg2+-dependent ATPase activity was activated by muscle f-actin. The pancreatic myosin bound to actin and could be dissociated by the addition of MgATP. Myosin purified from cells cultured in media containing [32P]Pi was phosphorylated on one of the light chains as well as the heavy chain. Thus pancreatic acinar cells contain a typical non-muscle myosin, and the subunits of this molecule are subject to post-translational modification by phosphorylation.

Electrophoretic and electron microscopic examination of the adductor and diductor muscles of an articulate brachiopod, Terebratalia transversa

1982 ◽  
Vol 60 (4) ◽  
pp. 550-559 ◽  
Author(s):  
William P. Eshleman ◽  
Jerrel L. Wilkens ◽  
Michael J. Cavey
Keyword(s):  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Electron Microscopic Examination ◽  
Light Chains ◽  
Electron Microscopic ◽  
Electrophoretic Patterns ◽  
Transmission Electron ◽  
Adductor Muscles ◽  
Regulation Of Contraction

The proteins of the striated adductor muscles, smooth adductor muscles, and diductor muscles of the articulate brachiopod Terebratalia transversa have been examined by sodium dodecyl sulfate – polyacrylamide gel electrophoresis. Electrophoretic patterns indicate the presence of paramyosin in all of these valve muscles. Tentative identification has also been made of the proteins responsible for actin and for myosin regulation of contraction (troponin–tropomyosin and myosin light chains, respectively). The myofilaments of the striated adductor cells, smooth adductor cells, and diductor cells have been characterized by transmission electron microscopy. The smooth adductor cells and the diductor cells exhibit very thick myofilaments which are fusiform in shape, exceptionally long, and axially banded. Morphological features of these thick myofilaments are consistent with those of paramyosin filaments found in other muscles and myoepithelia. Although the striated adductor cells contain paramyosin, it is not manifest in the thick myofilaments.

scholarly journals Solubilization of proteins from bovine brain coated vesicles by protein perturbants and Triton X-100.

1985 ◽  
Vol 101 (1) ◽  
pp. 12-18 ◽  
Author(s):  
B Wiedenmann ◽  
K Lawley ◽  
C Grund ◽  
D Branton
Keyword(s):  
Ionic Strength ◽  
Membrane Proteins ◽  
Periodic Acid ◽  
Electron Microscopic Examination ◽  
Bovine Brain ◽  
Coated Vesicles ◽  
Electron Microscopic ◽  
Periodic Acid Schiff ◽  
Peripheral Membrane Proteins ◽  
Triton X

To identify integral and peripheral membrane proteins, highly purified coated vesicles from bovine brain were exposed to solutions of various pH, ionic strength, and concentrations of the nonionic detergent Triton X-100. At pH 10.0 or above most major proteins were liberated, but four minor polypeptides sedimented with the vesicles. From quantitative analysis of phospholipids in the pellet and extract, we determined that at a pH of up to 12 all phospholipids could be recovered in the pellet. Electron microscopic examination of coated vesicles at pH 12.0 showed all vesicles devoid of coat structures. Treatment with high ionic strength solutions (0-1.0 M KCl) at pH 6.5-8.5 also liberated all major proteins, except tubulin, which remained sedimentable. The addition of Triton X-100 to coated vesicles or to stripped vesicles from which 90% of the clathrin had been removed resulted in the release of four distinct polypeptides of approximate Mr 38,000, 29,000, 24,000 and 10,000. The 38,000-D polypeptide (pK approximately 5.0), which represents approximately 50% of the protein liberated by Triton X-100, appears to be a glycoprotein on the basis of its reaction with periodic acid-Schiff reagent. Extraction of 90% of the clathrin followed by extraction of 90% of the phospholipids with Triton X-100 produced a protein residue that remained sedimentable and consisted of structures that appeared to be shrunken stripped vesicles. Together our data indicate that most of the major polypeptides of brain coated vesicles behave as peripheral membrane proteins and at least four polypeptides behave as integral membrane proteins. By use of a monoclonal antibody, we have identified one of these polypeptides (38,000 mol wt) as a marker for a subpopulation of calf brain coated vesicles.

scholarly journals PRESERVATION OF Na-K-ACTIVATED AND Mg-ACTIVATED ADENOSINE TRIPHOSPHATASE ACTIVITIES OF AVIAN SALT GLAND AND TELEOST GILL WITH FORMALDEHYDE AS FIXATIVE

1970 ◽  
Vol 18 (4) ◽  
pp. 251-263 ◽  
Author(s):  
STEPHEN A. ERNST ◽  
CHARLES W. PHILPOTT
Keyword(s):  
Atpase Activity ◽  
Adenosine Triphosphatase ◽  
Electron Microscopic Examination ◽  
Salt Gland ◽  
Chloride Cells ◽  
Secretory Cells ◽  
Salt Glands ◽  
Electron Microscopic ◽  
Fixed Tissue ◽  
Gill Filaments

The effect of glutaraldehyde and formaldehyde fixation on the level of biochemically demonstrable Na-K-adenosine triphosphatase (Na-K-ATPase) and Mg-ATPase of avian salt glands and teleost gill filaments was studied. Sections, 100-200 µ, prepared with the Smith-Farquhar tissue chopper, were fixed for varying periods, homogenized and assayed for ATPase activity. Fixation of salt gland tissue with 0.5% glutaraldehyde for 40-60 min completely inhibited the Na-K-ATPase activity and reduced the level of Mg-ATPase by 85%. In contrast, fixation with 2 or 3% formaldehyde, prepared from paraformaldehyde, for 60-90 min resulted in a loss of only 30% of the Na-K-ATPase activity and 65% of the Mg-ATPase activity. Similar results were obtained with gill filaments. In addition, Na-K-ATPase of formaldehyde-fixed tissue retained an obligatory requirement for Na+ and K+ and was fully sensitive to ouabain. Electron microscopic examination of formaldehyde-fixed tissue, sectioned with either the tissue chopper or in the cryostat and incubated in the Wachstein-Meisel medium, showed excellent morphologic preservation. Reaction product deposition (presumably due to Mg-ATPase) was associated with the extracellular side of the plasma membrane in the secretory cells of the salt gland and over the mitochondrial matrix of chloride cells present in the gill epithelium.

scholarly journals Insights into the Structural Organization of the I1 Inner Arm Dynein from a Domain Analysis of the 1β Dynein Heavy Chain

2000 ◽  
Vol 11 (7) ◽  
pp. 2297-2313 ◽  
Author(s):  
Catherine A. Perrone ◽  
Steven H. Myster ◽  
Raqual Bower ◽  
Eileen T. O'Toole ◽  
Mary E. Porter
Keyword(s):  
Heavy Chain ◽  
Structural Organization ◽  
Microscopic Analysis ◽  
Transcription Unit ◽  
Light Chains ◽  
Flagellar Motility ◽  
Electron Microscopic ◽  
Dynein Heavy Chain ◽  
Complex Transformation ◽  
Motility Mutant

To identify domains in the dynein heavy chain (Dhc) required for the assembly of an inner arm dynein, we characterized a new motility mutant (ida2-6) obtained by insertional mutagenesis.ida2-6 axonemes lack the polypeptides associated with the I1 inner arm complex. Recovery of genomic DNA flanking the mutation indicates that the defects are caused by plasmid insertion into theDhc10 transcription unit, which encodes the 1β Dhc of the I1 complex. Transformation with Dhc10 constructs encoding <20% of the Dhc can partially rescue the motility defects by reassembly of an I1 complex containing an N-terminal 1β Dhc fragment and a full-length 1α Dhc. Electron microscopic analysis reveals the location of the missing 1β Dhc motor domain within the axoneme structure. These observations, together with recent studies on the 1α Dhc, identify a Dhc domain required for complex assembly and further demonstrate that the intermediate and light chains are associated with the stem regions of the Dhcs in a distinct structural location. The positioning of these subunits within the I1 structure has significant implications for the pathways that target the assembly of the I1 complex into the axoneme and modify the activity of the I1 dynein during flagellar motility.

scholarly journals Carboxypeptidase A1 (CPA1) immunohistochemistry is highly sensitive and specific for acinar cell carcinoma (ACC) of the pancreas

2021 ◽  
Vol 156 (Supplement_1) ◽  
pp. S106-S107
Author(s):  
R Uhlig ◽  
T Clauditz
Keyword(s):  
Cell Carcinoma ◽  
Acinar Cell ◽  
Cell Damage ◽  
Acinar Cells ◽  
Acinar Cell Carcinoma ◽  
Pancreatic Acinar Cell ◽  
Pancreatic Acinar Cells ◽  
Specific Marker ◽  
Highly Sensitive ◽  
Pancreatic Acinar Cell Carcinoma

Abstract Introduction/Objective Introduction: Carboxypeptidase A1 (CPA1) is a zinc metalloprotease which is produced in pancreatic acinar cells and plays a role in cleaving C-terminal branched-chain and aromatic amino acids from dietary proteins. This study assessed the utility of immunohistochemical CPA1 staining for diagnosing pancreatic acinar cell carcinoma. Methods/Case Report Methods: A total of 15,680 tumor samples from 132 different tumor types and subtypes as well as 8 samples each of 76 different normal tissue types were analyzed by immunohistochemistry in a tissue microarray format. Results (if a Case Study enter NA) Results: CPA1 was strongly expressed in acinar cells of all normal pancreas samples but not in any other normal tissues. CPA1 immunostaining was detected in 100% of 11 pancreatic acinar cell carcinomas and one mixed acinar endocrine carcinoma (MAEC), but absent in 449 pancreatic ductal adenocarcinomas, 75 adenocarcinomas of the ampulla of Vater, and 11,739 other evaluable cancers from 128 different tumor entities. A weak to moderate diffuse staining of epithelial and stromal cells of cancer tissues immediately adjacent to non-neoplastic pancreatic acinar cells often occurred and was considered to be caused by diffusion of the highly abundant CPA1 from normal acinar cells that may have suffered some autolytic cell damage. Conclusion Our data show that CPA1 is a highly sensitive and largely specific marker for normal and neoplastic pancreatic acinar cells. CPA1 immunohistochemistry greatly facilitates the otherwise often difficult diagnosis of pancreatic acinar cell carcinoma.

Immunocytochemical Localization of Myosin Light Chains in the Abdominal Superficial Flexor Muscles of the American Lobster, Homarus Americanus

1998 ◽  
Vol 4 (S2) ◽  
pp. 1118-1119
Author(s):  
Lisa D. Brown ◽  
Marie E. Cantino
Keyword(s):  
Skeletal Muscle ◽  
Molecular Weight ◽  
Spatial Distribution ◽  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Homarus Americanus ◽  
Light Chains ◽  
Myosin Light Chains ◽  
Flexor Muscle ◽  
Electron Microscopic

Myosin is composed of two high-molecular weight heavy chains and four low-molecular weight hght chains. In both vertebrate and invertebrate skeletal muscle, each myosin heavy chain is associated with two myosin light chains. In skeletal muscle myosins studied by X-ray diffraction, each myosin heavy chain binds one of each of two distinct classes of hght chains. Thus, while isoform distributions may vary within and between fibers, the spatial distribution of each class of light chain should be uniform within the A band and between sarcomeres and fibers. Since no such study exists for crustacean myosin, we investigated the spatial distribution of the hght chains within the superficial flexor muscle (SFM) of the lobster, Homarus americanus, using immunoelectron microscopy. The SFM contains two classes of myosin hght chains, termed “alpha” (Mr = 21,000 to 23,500) and “beta” (Mr = 18,000 to 18,500). Immunocytochemical electron microscopic results suggest that the alpha light chains are not uniformly distributed at the subsarcomere level.

Laparoscopic distal pancreatectomy of an acinar cell carcinoma

Open Medicine ◽  
2008 ◽  
Vol 3 (4) ◽  
pp. 525-527
Author(s):  
Yin Hao ◽  
Shen Yong ◽  
Deng Xing ◽  
Peng Hong
Keyword(s):  
Cell Carcinoma ◽  
Distal Pancreatectomy ◽  
Acinar Cell ◽  
Good Condition ◽  
Electron Microscopic Examination ◽  
Acinar Cell Carcinoma ◽  
Laparoscopic Distal Pancreatectomy ◽  
Pancreatic Tumors ◽  
Electron Microscopic ◽  
Operative Strategy

AbstractAcinar cell carcinoma (ACC) of the pancreas is relatively rare, accounting for only approximately 1% of all exocrine pancreatic tumors. Because ACC of the pancreas is rare, strategy for management needs to be explored. The patient was a 50-year-old man who presented with left upper quadrant pain over 6 months. A mass lesion, located at the pancreatic tail, measuring approximately 4 cm in diameter was found on ultrasound, abdominal dynamic CT. The patient underwent a laparoscopic distal pancreatectomy. Immunohistochemical stains and electron microscopic examination of the tumor was consistent with ACC. No complication occurred, and the patient was discharged in good condition on 10th postoperative day. During the 10 months of follow-up, CT and tumor markers revealed no recurrence. In conclusions, Laparoscopic distal pancreatectomy can be performed safely for selected patients with nonmetastatic ACC at a favorable anatomic position. This operative strategy offers a minimally invasive surgery with the aim of a potential cure.

scholarly journals Dictyostelium myosin: characterization of chymotryptic fragments and localization of the heavy-chain phosphorylation site.

1981 ◽  
Vol 89 (1) ◽  
pp. 104-108 ◽  
Author(s):  
G Peltz ◽  
E R Kuczmarski ◽  
J A Spudich
Keyword(s):  
Molecular Weight ◽  
Ionic Strength ◽  
Atpase Activity ◽  
Heavy Chain ◽  
Polyacrylamide Gel Electrophoresis ◽  
Phosphorylation Site ◽  
Polyacrylamide Gel ◽  
Maximal Velocity ◽  
Dictyostelium Myosin ◽  
Low Ionic Strength

Chymotrypsin cleaves Dictyostelium myosin in half, splitting the heavy chain (210,000 daltons) into two fragments of 105,000 daltons each. One of the two major fragments is soluble at low ionic strength and has a native molecular weight of 130,000. As judged by SDS polyacrylamide gel electrophoresis, this soluble fragment consists of the two intact myosin light chains of 18,000 and 16,000 daltons and a 105,000-dalton polypeptide derived from the myosin heavy chain. The soluble fragment retains actin-activated ATPase activity and the ability to bind to actin in an ATP-dissociable fashion. The maximal velocity of the actin-activated ATPase activity of the soluble fragment is 80% of that of uncleaved myosin, although its apparent Km for actin is 12-fold greater than that of myosin. In addition to the major soluble 105,000-dalton fragment discussed above, chymotryptic cleavage of the Dictyostelium myosin also generates fragments that are insoluble at low ionic strength. The major insoluble fragment is 105,000 daltons on an SDS polyacrylamide gel and forms thick filaments that are devoid of myosin heads. A less prevalent insoluble fragment has a molecular weight of 83,000 and is probably a subfragment of the insoluble 105,000-dalton fragment. The heavy chain of myosin is phosphorylated in vivo and the phosphorylation site has been localized to the insoluble fragments, which derive from the tail portion of the myosin molecule.

scholarly journals UCS protein Rng3p activates actin filament gliding by fission yeast myosin-II

2004 ◽  
Vol 167 (2) ◽  
pp. 315-325 ◽  
Author(s):  
Matthew Lord ◽  
Thomas D. Pollard
Keyword(s):  
Atpase Activity ◽  
Heavy Chain ◽  
Actin Filaments ◽  
Myosin Ii ◽  
Gliding Motility ◽  
Light Chains ◽  
Temperature Sensitive ◽  
Contractile Ring ◽  
In Vitro Motility

We purified native Myo2p/Cdc4p/Rlc1p (Myo2), the myosin-II motor required for cytokinesis by Schizosaccharomyces pombe. The Myo2p heavy chain associates with two light chains, Cdc4p and Rlc1p. Although crude Myo2 supported gliding motility of actin filaments in vitro, purified Myo2 lacked this activity in spite of retaining full Ca-ATPase activity and partial actin-activated Mg-ATPase activity. Unc45-/Cro1p-/She4p-related (UCS) protein Rng3p restored the full motility and actin-activated Mg-ATPase activity of purified Myo2. The COOH-terminal UCS domain of Rng3p alone restored motility to pure Myo2. Thus, Rng3p contributes directly to the motility activity of native Myo2. Consistent with a role in Myo2 activation, Rng3p colocalizes with Myo2p in the cytokinetic contractile ring. The absence of Rlc1p or mutations in the Myo2p head or Rng3p compromise the in vitro motility of Myo2 and explain the defects in cytokinesis associated with some of these mutations. In contrast, Myo2 with certain temperature-sensitive forms of Cdc4p has normal motility, so these mutations compromise other functions of Cdc4p required for cytokinesis.

Functional Acinar Cell Carcinoma of the Pancreas

1973 ◽  
Vol 31 ◽  
pp. 376-377
Author(s):  
W. A. Burns ◽  
G. C. Vander Weide ◽  
M. J. Matthews
Keyword(s):  
Liver Metastases ◽  
Cell Carcinoma ◽  
Acinar Cell ◽  
Malignant Tumors ◽  
Acinar Cell Carcinoma ◽  
Skin Lesions ◽  
Pancreatic Acinar Cells ◽  
Electron Microscopic ◽  
Carcinoma Of The Pancreas ◽  
Chemical Studies

Malignant tumors arising from pancreatic acinar cells are relatively uncommon. Rarely these tumors may be functional, secrete amylase or lipase and present clinically with polyarthropathies and skin lesions resembling erythema nodosum. Some of the reported cases were supported with confirmative data, but none to our knowledge had chemical and ultrastructural confirmation. We wish to report the electron microscopic and bio-chemical studies of a functional acinar cell carcinoma of the pancreas.The patient was a 52 year old, black male who had constant complaints of polyarthropathy and was found to have a tumor of the pancreas with liver metastases.Tissue from a pre-mortem liver biopsy and post-mortem from the pancreatic tumor and the liver metastases were examined.

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