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Brünagel G, Schoen RE, Getzenberg RH. Colon cancer specific nuclear matrix protein alterations in human colonic adenomatous polyps. J Cell Biochem 2004; 91:365-74. [PMID: 14743395 DOI: 10.1002/jcb.10695] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Most colon cancers arise within preexisting adenomatous polyps or adenomas. The slow evolution from the non-invasive premalignant lesion, the adenomatous polyp, to invasive cancer supports a strategy of early detection. Recently, we identified unique nuclear matrix proteins (NMPs) specific for colon cancer (CC2, CC3, CC4, CC5). Most of the NMPs identified are common to all cell types, but several identified NMPs are tissue and cell line specific. The objective of this study is to describe and characterize the NMP profile of premalignant adenomatous colon polyps. Specifically when in the adenoma-carcinoma sequence four specific colon cancer NMPs, previously described, appear. Using two-dimensional (2-D) gel analysis 20 colon polyps (one juvenile polyp, six tubular adenoma (TA), seven tubulovillous adenoma (TVA), six TVA with focal high-grade dysplasia (HGD), were analyzed for the presence of four (CC2, CC3, CC4, CC5) specific NMPs. CC2 was not seen in any of the premalignant polyps. CC5 was present in only two premalignant TVA with HGD and in one TA. CC3 and CC4 were present in most adenomas. None of the NMPs were seen in the juvenile polyp, which is not considered to be a precursor of colon cancer. CC2 and CC5 are NMPs expressed at the junction of an advanced adenoma and invasive colorectal cancer. CC3 and CC4 are expressed earlier in the evolution of adenomatous polyps. Development of an assay to these proteins may serve as a new method for early detection of colorectal cancer.
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Affiliation(s)
- Gisela Brünagel
- Department of Medicine, University of Pittsburgh School of Medicine and University of Pittsburgh Cancer Institute, Pittsburgh, Pennsylvania 15232, USA
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2
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Boccardo F, Rubagotti A, Carmignani G, Romagnoli A, Nicolò G, Barboro P, Parodi S, Patrone E, Balbi C. Nuclear matrix proteins changes in cancerous prostate tissues and their prognostic value in clinically localized prostate cancer. Prostate 2003; 55:259-64. [PMID: 12712405 DOI: 10.1002/pros.10248] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND After the discovery that nuclear matrix (NM) directs the spatial organization of DNA transcription and replication, there has been an increasing interest in studying NM changes associated with malignant transformation and their potential usefulness in the clinical setting. METHODS High-resolution two-dimensional gel electrophoresis was used to analyze the NM proteins (NMP) of specimens of prostate cancer tissue obtained from the prostates of 75 patients undergoing retropubic prostatectomy. RESULTS Nine NMP with different molecular weights and isoelectric points have been identified. They were expressed differently by prostate cancer tissues. An increasing trend toward the expression of such proteins like NMP 6-8 was evident with increasing tumor stage and dedifferentiation. NMP 6-8 were also significantly correlated with the risk of biochemical progression. However, Gleason score was the only significant discriminant in this regard in multiparametric models. CONCLUSIONS This study confirms that prostate cancer progression is related to profound changes in NMP expression patterns. However, due to the complexity of the methods required to define these latter, the clinical relevance of NMP appears to be still limited.
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Affiliation(s)
- Francesco Boccardo
- Professorial Unit of Medical Oncology, University and National Cancer Research Institute of Genoa, Italy.
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3
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Brünagel G, Shah U, Schoen RE, Getzenberg RH. Identification of calreticulin as a nuclear matrix protein associated with human colon cancer. J Cell Biochem 2003; 89:238-43. [PMID: 12704787 DOI: 10.1002/jcb.10502] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Colon cancer is one of the most common malignancies among populations in the United States and Western Europe, and one of the leading causes of worldwide morbidity and mortality due to cancer. The early detection of colon cancer is central to the effective treatment of this disease and early detection markers are needed. We have demonstrated that high-resolution two-dimensional gel analysis of nuclear matrix proteins (NMPs) demonstrated a specific oncological fingerprint of colon cancer. Utilizing this approach, four proteins specific for colon cancer was identified. Additionally, one protein was expressed much more strongly in colon cancer compared to adjacent and normal donor tissue. The amino acid composition of this protein revealed sequence similarity with calreticulin. The multi-functional protein, calreticulin, is normally found in the lumen of the endoplasmic reticulum although some reports have described a nuclear localization of the protein. The aim of this study was to confirm the identity of the protein as calreticulin as well as to evaluate the localization of calreticulin in the nuclear matrix of colon cancer tissue.
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Affiliation(s)
- Gisela Brünagel
- Division of Gastroenterology, Department of Medicine, University of Pittsburgh School of Medicine and University of Pittsburgh Cancer Institute, Pittsburgh, Pennsylvania 15232, USA
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Alberti I, Barboro P, Barbesino M, Sanna P, Pisciotta L, Parodi S, Nicol� G, Boccardo F, Galli S, Patrone E, Balbi C. Changes in the expression of cytokeratins and nuclear matrix proteins are correlated with the level of differentiation in human prostate cancer. J Cell Biochem 2000. [DOI: 10.1002/1097-4644(20001201)79:3<471::aid-jcb120>3.0.co;2-o] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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5
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Keesee SK, Marchese J, Meneses A, Potz D, Garcia-Cuellar C, Szaro RP, Solorza G, Osornio-Vargas A, Mohar A, de la Garza JG, Wu YJ. Human cervical cancer-associated nuclear matrix proteins. Exp Cell Res 1998; 244:14-25. [PMID: 9770344 DOI: 10.1006/excr.1998.4202] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The nuclear matrix is the nonchromatin protein structural component of the nucleus that governs nuclear shape and also exerts regulatory control over higher order gene organization. Recent studies have documented the presence of tumor-associated nuclear matrix proteins in several human cancers. We used high-resolution two-dimensional gel electrophoresis to compare nuclear matrix protein patterns in cervical carcinomas with those from normal cervical tissue. Tumors obtained from 20 patients undergoing hysterectomy for clinically localized cervical cancer were compared with normal cervical tissue. We have identified five polypeptides (CvC-1: Mr = 69,408 Da, pI = 5. 78; CvC-2: Mr = 53,752 Da, pI = 5.54; CvC-3: Mr = 47,887 Da, pI = 5. 60; CvC-4: Mr = 46,006 Da, pI = 5.07; and CvC-5: Mr = 44,864 Da, pI = 6.61) in the nuclear matrix from cervical carcinomas that were present in 20 of 20 cervical tumors but 0 of 10 normal tissues. These data extend similar findings of cancer-associated nuclear matrix proteins in other human cancers and suggest that nuclear matrix proteins may represent a new class of cancer markers that could aid the diagnosis or management of some types of cancer.
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Affiliation(s)
- S K Keesee
- Matritech, Inc., 330 Nevada Street, Newton, Massachusetts, 02160, USA.
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6
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Grondin B, Côté F, Bazinet M, Vincent M, Aubry M. Direct interaction of the KRAB/Cys2-His2 zinc finger protein ZNF74 with a hyperphosphorylated form of the RNA polymerase II largest subunit. J Biol Chem 1997; 272:27877-85. [PMID: 9346935 DOI: 10.1074/jbc.272.44.27877] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
We previously identified ZNF74 as a developmentally expressed gene commonly deleted in DiGeorge syndrome. ZNF74 encodes an RNA-binding protein tightly associated with the nuclear matrix and belongs to a large subfamily of Cys2-His2 zinc finger proteins containing a KRAB (Kruppel-associated box) repressor motif. We now report on the multifunctionality of the zinc finger domain of ZNF74. This nucleic acid binding domain is shown here to function as a nuclear matrix targeting sequence and to be involved in protein-protein interaction. By far-Western analysis and coimmunoprecipitation studies, we demonstrate that ZNF74 interacts, via its zinc finger domain, with the hyperphosphorylated largest subunit of RNA polymerase II (pol IIo) but not with the hypophosphorylated form. The importance of the phosphorylation in this interaction is supported by the observation that phosphatase treatment inhibits ZNF74 binding. Double immunofluorescence experiments indicate that ZNF74 colocalizes with the pol IIo and the SC35 splicing factor in irregularly shaped subnuclear domains. Thus, ZNF74 sublocalization in nuclear domains enriched in pre-mRNA maturating factors, its RNA binding activity, and its direct phosphodependent interaction with the pol IIo, a form of the RNA polymerase functionally associated with pre- mRNA processing, suggest a role for this member of the KRAB multifinger protein family in RNA processing.
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Affiliation(s)
- B Grondin
- Institut de Recherches Cliniques de Montréal et Département de Médecine, Université de Montréal, Montréal, Québec H2W 1R7, Canada
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7
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Raziuddin A, Court D, Sarkar FH, Liu YL, Kung HF, Raziuddin R. A c-erbB-2 promoter-specific nuclear matrix protein from human breast tumor tissues mediates NF-kappaB DNA binding activity. J Biol Chem 1997; 272:15715-20. [PMID: 9188464 DOI: 10.1074/jbc.272.25.15715] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The c-erbB-2 gene overexpression plays a major role in the pathogenesis of breast cancer. Binding studies detected a nuclear matrix protein (NMP) in human breast tumor tissues that recognizes a matrix attachment region (MAR) in the immediate vicinity of the c-erbB-2 gene promoter. This NMP is expressed in breast tumor tissues and cell lines along with c-erbB-2, but is not found in corresponding normal tissues. Furthermore, when NMP purified from the breast tumors by its affinity to the MAR sequence is added to nuclear extracts of breast cancer cells, it selectively stimulates the binding of the NF-kappaB transcription factor to DNA. A model is suggested in which the association of the MAR-like sequence with the nuclear matrix raises the local concentration of the specific NMP, which in turn interacts with the nuclear factor NF-kappaB to increase its local level. Such a complex could explain at a molecular level the "increase in NF-kappaB DNA binding activity" often observed in c-erbB-2- and BRCA1-positive human breast tumors. The increased NF-kappaB activity could thereby contribute to breast cancer progression.
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Affiliation(s)
- A Raziuddin
- Intramural Research Support Program, Science Application International Corporation/Frederick, NCI-Frederick Cancer Research and Development Center, Frederick, Maryland 21702, USA
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8
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Vamvakas S, Richter H, Bittner D. Poly(ADP-ribosyl)ation and nuclear matrix/intermediate filament proteins in renal carcinogenesis. Recent Results Cancer Res 1997; 143:195-208. [PMID: 8912420 DOI: 10.1007/978-3-642-60393-8_13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- S Vamvakas
- Department of Toxicology, University of Würzburg, Germany
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9
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Davie JR. The nuclear matrix and the regulation of chromatin organization and function. INTERNATIONAL REVIEW OF CYTOLOGY 1996; 162A:191-250. [PMID: 8575881 DOI: 10.1016/s0074-7696(08)61232-2] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Nuclear DNA is organized into loop domains, with the base of the loop being bound to the nuclear matrix. Loops with transcriptionally active and/or potentially active genes have a DNase I-sensitive chromatin structure, while repressed chromatin loops have a condensed configuration that is essentially invisible to the transcription machinery. Core histone acetylation and torsional stress appear to be responsible for the generation and/or maintenance of the open potentially active chromatin loops. The transcriptionally active region of the loop makes several dynamic attachments with the nuclear matrix and is associated with core histones that are dynamically acetylated. Histone acetyltransferase and deacetylase, which catalyze this rapid acetylation and deacetylation, are bound to the nuclear matrix. Several transcription factors are components of the nuclear matrix. Histone acetyltransferase, deacetylase, and transcription factors may contribute to the dynamic attachment of the active chromatin domains with the nuclear matrix at sites of ongoing transcription.
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Affiliation(s)
- J R Davie
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Manitoba, Winnipeg, Canada
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10
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Chabot B, Bisotto S, Vincent M. The nuclear matrix phosphoprotein p255 associates with splicing complexes as part of the [U4/U6.U5] tri-snRNP particle. Nucleic Acids Res 1995; 23:3206-13. [PMID: 7667097 PMCID: PMC307179 DOI: 10.1093/nar/23.16.3206] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The monoclonal antibody CC3 recognizes a phosphorylated epitope present on an interphase protein of 255 kDa. Previous work has shown that p255 is localized mainly to nuclear speckles and remains associated with the nuclear matrix scaffold following extraction with non-ionic detergents, nucleases and high salt. The association of p255 with splicing complexes is suggested by the finding that mAb CC3 can inhibit in vitro splicing and immunoprecipitate pre-messenger RNA and splicing products. Small nuclear RNA immunoprecipitation assays show that p255 is a component of the U5 small nuclear ribonucleoprotein (snRNP) and the [U4/U6.U5] tri-snRNP complex. In RNase protection assays, mAb CC3 immunoprecipitates fragments containing branch site and 3' splice site sequences. As predicted for a [U4/U6.U5]-associated component, the recovery of the branch site-protected fragment requires binding of U2 snRNP and is inhibited by EDTA. p255 may correspond to the previously identified p220 protein, the mammalian analogue of the yeast PRP8 protein. Our results suggest that changes in the phosphorylation of p255 may be part of control mechanisms that interface splicing activity with nuclear organization.
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Affiliation(s)
- B Chabot
- Département de Microbiologie, Faculté de Médecine, Université de Sherbrooke, Québec, Canada
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11
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Neri LM, Riederer BM, Marugg RA, Capitani S, Martelli AM. The effect of sodium tetrathionate stabilization on the distribution of three nuclear matrix proteins in human K562 erythroleukemia cells. Histochem Cell Biol 1995; 104:29-36. [PMID: 7584557 DOI: 10.1007/bf01464783] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Using both conventional fluorescence and confocal laser scanning microscopy we have investigated whether or not stabilization of isolated human erythroleukemic nuclei with sodium tetrathionate can maintain in the nuclear matrix the same spatial distribution of three polypeptides (M(r) 160 kDa and 125 kDa, previously shown to be components of the internal nuclear matrix plus the 180-kDa nucleolar isoform of DNA topoisomerase II) as seen in permeabilized cells. The incubation of isolated nuclei in the presence of 2 mM sodium tetrathionate was performed at 0 degrees C or 37 degrees C. The matrix fraction retained 20-40% of nuclear protein, depending on the temperature at which the chemical stabilization was executed. Western blot analysis revealed that the proteins studied were completely retained in the high-salt resistant matrix. Indirect immunofluorescence experiments showed that the distribution of the three antigens in the final matrix closely resembled that detected in permeabilized cells, particularly when the stabilization was performed at 37 degrees C. This conclusion was also strengthened by analysis of cells, isolated nuclei and the nuclear matrix by means of confocal laser scanning microscopy. We conclude that sodium tetrathionate stabilization of isolated nuclei does not alter the spatial distribution of some nuclear matrix proteins.
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Affiliation(s)
- L M Neri
- Istituto di Anatomia Umana Normale, Università di Ferrara, Italy
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12
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Bisotto S, Lauriault P, Duval M, Vincent M. Colocalization of a high molecular mass phosphoprotein of the nuclear matrix (p255) with spliceosomes. J Cell Sci 1995; 108 ( Pt 5):1873-82. [PMID: 7657711 DOI: 10.1242/jcs.108.5.1873] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
It was previously demonstrated that monoclonal antibody CC-3 binds to a phosphorylation dependent epitope present on a 255 kDa nuclear protein (p255). We show here that in interphase cells, p255 distributes to typical nuclear speckles that correspond to the localization of spliceosome components as revealed by antibodies to the m3G cap of snRNAs or to the non-snRNP splicing factor SC-35. Immunofluorescence and immunoblot studies indicated that p255 is resistant to extraction with non-ionic detergents, nucleases and high ionic strength buffers and may thus be defined biochemically as a nuclear matrix phosphoprotein. To determine the nature of the association of p255 with the nuclear structure, its distribution was studied at different stages of the cell cycle and after the cells were treated with nucleases or heat shocked. We found that the antigen diffused into the cytoplasm during metaphase but was reorganized into cytoplasmic speckles during anaphase-telophase transition, where it colocalized with SC-35. Nuclear matrix preparations that were digested with DNases and RNases showed that interphasic p255 still localized to nuclear speckles even though snRNA and snRNP antigens were removed. Heat-shocked cells labelled with monoclonal antibody CC-3 exhibited more rounded and less interconnected speckles, identical to those decorated by anti-SC-35 antibody under such conditions. These results indicate that p255 and SC-35 are present in the same nuclear structures, to which they are more tightly bound than the snRNP antigens. They further suggest that both proteins are implicated in spliceosome assembly or attachment.
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Affiliation(s)
- S Bisotto
- CHUL Research Center, Laval University, Ste-Foy, Québec, Canada
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13
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Keesee SK, Meneghini MD, Szaro RP, Wu YJ. Nuclear matrix proteins in human colon cancer. Proc Natl Acad Sci U S A 1994; 91:1913-6. [PMID: 8127905 PMCID: PMC43274 DOI: 10.1073/pnas.91.5.1913] [Citation(s) in RCA: 56] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The nuclear matrix is the nonchromatin scaffolding of the nucleus. This structure confers nuclear shape, organizes chromatin, and appears to contain important regulatory proteins. Tissue specific nuclear matrix proteins have been found in the rat, mouse, and human. In this study we compared high-resolution two-dimensional gel electropherograms of nuclear matrix protein patterns found in human colon tumors with those from normal colon epithelia. Tumors were obtained from 18 patients undergoing partial colectomy for adenocarcinoma of the colon and compared with tissue from 10 normal colons. We have identified at least six proteins which were present in 18 of 18 colon tumors and 0 of 10 normal tissues, as well as four proteins present in 0 of 18 tumors and in 10 of 10 normal tissues. These data, which corroborate similar findings of cancer-specific nuclear matrix proteins in prostate and breast, suggest that nuclear matrix proteins may serve as important markers for at least some types of cancer.
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14
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Brancolini C, Schneider C. Phosphorylation of the growth arrest-specific protein Gas2 is coupled to actin rearrangements during Go-->G1 transition in NIH 3T3 cells. J Biophys Biochem Cytol 1994; 124:743-56. [PMID: 8120096 PMCID: PMC2119946 DOI: 10.1083/jcb.124.5.743] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Growth arrest-specific (Gas2) protein has been shown to be a component of the microfilament system, that is highly expressed in growth arrested mouse and human fibroblasts and is hyperphosphorylated upon serum stimulation of quiescent cells. (Brancolini, C., S. Bottega, and C. Schneider. 1992. J. Cell Biol. 117:1251-1261). In this study we demonstrate that the kinetics of Gas2 phosphorylation, during Go-->G1 transition, as induced by addition of 20% FCS to serum starved NIH 3T3 cells, is temporally coupled to the reorganization of actin cytoskeleton. To better dissect the relationship between Gas2 phosphorylation and the modification of the microfilament architecture we used specific stimuli for both membrane ruffling (PDGF and PMA) and stress fiber formation (L-alpha-lysophosphatidic acid LPA) (Ridley, A. J., and A. Hall. 1992. Cell. 70:389-399). All of them, similarly to 20% FCS, are able to downregulate Gas2 biosynthesis. PDGF and PMA induce Gas2 hyperphosphorylation that is temporally coupled with the appearance of membrane ruffling where Gas2 localizes. On the other hand LPA, a specific stimulus for stress fiber formation, fails to induce a detectable Gas2 hyperphosphorylation. Thus, Gas2 hyperphosphorylation is specifically correlated with the formation of membrane ruffling possibly implying a role of Gas2 in this process.
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Affiliation(s)
- C Brancolini
- Laboratorio Nazionale Consorzio Interuniversitario, Biotecnologie, AREA Science Park, Trieste, Italy
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15
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Partin AW, Coffey DS. Benign and malignant prostatic neoplasms: human studies. RECENT PROGRESS IN HORMONE RESEARCH 1994; 49:293-331. [PMID: 7511829 DOI: 10.1016/b978-0-12-571149-4.50020-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Because the present ability to treat and cure patients with prostate cancer is limited to those patients with pathologically organ-confined disease, it has become increasingly important to diagnose this disease at an early stage, when cure is most likely. Recent advances in imaging may allow the urologist and the pathologist to make the diagnosis of prostate cancer much earlier in the natural course of the disease. It therefore becomes imperative to have methods available to predict which patients have a high probability of progressing so that treatment can be assigned logically and appropriately. Our current methods of prognosis determination (stage and grade) do not allow accurate assessment of tumor behavior in the majority of individual patients with prostate cancer. Therefore, more accurate quantification of nuclear and cellular changes that take place as a tumor progresses to take on the aggressive (metastatic) phenotype are urgently needed. Experimental techniques have proven useful in answering these questions and now seem ready for large-scale testing in clinical studies.
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Affiliation(s)
- A W Partin
- Department of Urology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287
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Brancolini C, Bottega S, Schneider C. Gas2, a growth arrest-specific protein, is a component of the microfilament network system. J Cell Biol 1992; 117:1251-61. [PMID: 1607387 PMCID: PMC2289493 DOI: 10.1083/jcb.117.6.1251] [Citation(s) in RCA: 104] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
In this report we analyze the protein product of a growth arrest-specific gene, gas2, by means of an affinity-purified antibody raised against the protein produced in bacteria. The regulation of Gas2 biosynthesis reflects the pattern of mRNA expression (Schneider, C., R. King, and L. Philipson. 1988. Cell. 54:787-793): its relative level is tightly associated with growth arrest. Gas2 seems to be regulated also at the posttranslational level via a phosphorylation mechanism. Gas2 is well conserved during the evolution with the same apparent molecular mass (36 kD) between mouse and human. We also demonstrate that Gas2 is a component of the microfilament system. It colocalizes with actin fiber, at the cell border and also along the stress fiber, in growth-arrested NIH 3T3 cells. The pattern of distribution, detected in arrested cells, can also be observed in growing cells when they are microinjected with the purified GST-Gas2 protein. In none of the analyzed oncogene-transformed NIH 3T3 cell lines was Gas2 expression induced under serum starvation.
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Affiliation(s)
- C Brancolini
- International Center for Genetic Engineering and Biotechnology (I.C.G.E.B.) Trieste, Italy
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