Molecular and Functional Characterization of Protein 4.1B, a Novel Member of the Protein 4.1 Family with High Level, Focal Expression in Brain

Parra, Marilyn; Gascard, Philippe; Walensky, Loren D.; Gimm, J. Aura; Blackshaw, Seth; Chan, Nadine; Takakuwa, Yuichi; Berger, Trish; Lee, Gloria; Chasis, Joel Anne; Snyder, Solomon H.; Mohandas, Narla; Conboy, John G.

doi:10.1074/jbc.275.5.3247

Cited by 123 publications

(145 citation statements)

References 55 publications

Supporting

Mentioning

134

Contrasting

Unclassified

Order By: Relevance

“…Cultured astrocytes also expressed a 126-kDa Band 4.1B immunoreactive band (Fig. 4C); this molecular weight coincides with the size for Band 4.1B protein described in previous reports (12,13). The relative amount of Band 4.1B does not change in ␣v Ϫ/Ϫ astrocytes or neonatal brains (Fig.…”

Section: Band 41b Selectively Interacts With ␤8mentioning

confidence: 57%

See 1 more Smart Citation

An interaction between αvβ8 integrin and Band 4.1B via a highly conserved region of the Band 4.1 C-terminal domain

McCarty

Cook

Hynes

2005

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

␣v␤8 integrin is highly expressed in the vertebrate CNS, and mice lacking the ␣v or ␤8 genes develop cerebral hemorrhage due to defective interactions between blood vessels and ␣v␤8-expressing neural cells. Although ␣v␤8 binds many of the same extracellular matrix protein ligands as other integrins, very little is known about the intracellular signal transduction events used by ␣v␤8 to regulate CNS development. Here we identify Band 4.1B as an intracellular factor that interacts selectively with the ␤8 cytoplasmic tail. The association with ␣v␤8 occurs via the band 4.1B C-terminal domain, a region highly conserved among the various Band 4.1 family members. Indeed, we show that ␤8 integrin interacts directly with the C-terminal domains of several Band 4.1 proteins and colocalizes with them in cultured astrocytes and in the brain. These data identify a previously uncharacterized interaction between an integrin and Band 4.1 family members and suggest an important functional role for ␣v␤8 -Band 4.1 interactions in the development and maintenance of the CNS.central nervous system ͉ extracellular matrix ͉ intracellular signal transduction

show abstract

Section: Band 41b Selectively Interacts With ␤8mentioning

confidence: 57%

“…A single clone identified from the Y2H library encoded Band 4.1B ( Fig. 1 C and D), a member of the Band 4.1 family of proteins (12,13). Mammalian Band 4.1 proteins contain three distinct functional domains: an N-terminal FERM domain, a central spectrin͞actin-binding domain, and a CTD (6,14,15).…”

Section: Band 41b Selectively Interacts With ␤8mentioning

confidence: 99%

An interaction between αvβ8 integrin and Band 4.1B via a highly conserved region of the Band 4.1 C-terminal domain

McCarty

Cook

Hynes

2005

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

show abstract

“…Using an antibody that recognizes ezrin and crossreacts with radixin and moesin, these proteins were found to be present at high levels at the apical membranes in the virgin mammary gland (Figure 2a, arrow). We further found that ERM expression decreases dramatically during the proliferative stage of pregnancy and the differentiated stage of lactation before returning to high levels during late involution (Figure 2b- (Tran et al, 1999;Parra et al, 2000;Charboneau et al, 2002), we found that 4.1B also localizes to the membrane and cytoplasm in individual MDA-MB 436 cells, which do not form normal cell-cell contacts ( Figure 3b), and is concentrated at the tips of cell processes at apparent points of adhesion to the culture dish. Interestingly, 4.1B expression could be detected around and in the nuclei of these cells even though no such nuclear localization was apparent in mammary tissue sections.…”

Section: Erm Proteins Are Downregulated During Pregnancymentioning

confidence: 86%

“…All 4.1 family members are characterized by the presence of a conserved N-terminal membrane-association FERM (Fourpoint-one, Ezrin, Radixin, Moesin) domain (Chishti et al, 1998). In addition, most 4.1 proteins can associate with the spectrin-actin cytoskeleton by virtue of an actin-binding domain (Parra et al, 2000;Gimm et al, 2002). Both 4.1 and ERM proteins can act as structural proteins that link the plasma membrane to the actin cytoskeleton (Tsukita et al, 1994).…”

Section: Introductionmentioning

confidence: 99%

“…Protein 4.1B is a brain-enriched ortholog of 4.1R that localizes to points of cell-cell contact at the plasma membrane (Peters et al, 1998;Parra et al, 2000). Several studies have indicated that 4.1B expression is lost or reduced in numerous malignant and benign tumors, including 54% of nonsmall cell lung carcinomas (NSCLC) (Tran et al, 1999).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Protein 4.1B expression is induced in mammary epithelial cells during pregnancy and regulates their proliferation

et al. 2005

View full text Add to dashboard Cite

4.1B is a member of the protein 4.1 superfamily of proteins that link transmembrane proteins to the actin cytoskeleton. The 4.1B gene localizes to chromosome 18p11.3, which undergoes loss of heterozygosity in mammary tumors. Here, we examine the expression of 4.1B in murine mammary epithelium and find that 4.1B is dramatically upregulated in mammary epithelial cells during pregnancy when there is extensive cell proliferation. In contrast, 4.1B is not expressed in virgin, lactating, or involuting mammary epithelium. To examine the consequence of 4.1B loss on mammary epithelial cell proliferation, we analysed mammary glands in 4.1B-null mice. 4.1B loss results in a significant increase in mammary epithelial cell proliferation during pregnancy, but has no effect on mammary epithelial cell proliferation, in virgin or involuting mice. Furthermore, we show that 4.1B inhibits the proliferation of mammary epithelial cell lines by inducing a G 1 cell cycle arrest, characterized by decreased cyclin A expression and reduced Rb phosphorylation, and accompanied by reduced erbB2 phosphorylation. This cell cycle arrest does not involve alterations in the activities of MAPK, JNK, or Akt. Collectively, our findings demonstrate that 4.1B regulates mammary epithelial cell proliferation during pregnancy and suggest that its loss may influence mammary carcinoma pathogenesis in multiparous women.

show abstract

Acute demyelination disrupts the molecular organization of peripheral nervous system nodes

Arroyo

Sirkowski

Chitale

et al. 2004

J of Comparative Neurology

View full text Add to dashboard Cite

Intraneurally injected lysolecithin causes both segmental and paranodal demyelination. In demyelinated internodes, axonal components of nodes fragment and disappear, glial and axonal paranodal and juxtaparanodal proteins no longer cluster, and axonal Kv1.1/Kv1.2 K+ channels move from the juxtaparanodal region to appose the remaining heminodes. In paranodal demyelination, a gap separates two distinct heminodes, each of which contains the molecular components of normal nodes; paranodal and juxtaparanodal proteins are properly localized. As in normal nodes, widened nodal regions contain little or no band 4.1B. Lysolecithin also causes "unwinding" of paranodes: The spiral of Schwann cell membrane moves away from the paranodes, but the glial and axonal components of septate-like junctions remain colocalized. Thus, acute demyelination has distinct effects on the molecular organization of the nodal, paranodal, and juxtaparanodal region, reflecting altered axon-Schwann cell interactions.

show abstract

Molecular and Functional Characterization of Protein 4.1B, a Novel Member of the Protein 4.1 Family with High Level, Focal Expression in Brain

Cited by 123 publications

References 55 publications

An interaction between αvβ8 integrin and Band 4.1B via a highly conserved region of the Band 4.1 C-terminal domain

An interaction between αvβ8 integrin and Band 4.1B via a highly conserved region of the Band 4.1 C-terminal domain

Protein 4.1B expression is induced in mammary epithelial cells during pregnancy and regulates their proliferation

Acute demyelination disrupts the molecular organization of peripheral nervous system nodes

Contact Info

Product

Resources

About