Disease relevance of SP4

• High levels of SPR1 are detected in various diseases and cancers of the skin or respiratory epithelia and in nonkeratinizing papillary adenocarcinomas [1].
• Since immunohistochemical demonstration of cyclin D1 is notoriously difficult, this study aims to assess whether a newly available rabbit MAb against cyclin D1 (SP4) can improve the consistency of immunostaining, especially for the diagnosis of mantle cell lymphoma (MCL) [2].
• These data suggest that the PBC-specific antigen recognized by C355.1 and SP4 in bile duct epithelial cells is expressed aberrantly in the salivary gland in 66% of patients with PBC, independent of Sjogren's syndrome [3].
• The immunoperoxidase technique was used to study the occurrence of placenta-associated plasma protein A (PAPP-A, SP4) in formalin-fixed paraffin-embedded tissue specimens from 15 hydatidiform moles, 6 invasive moles and 7 choriocarcinomas [4].
• A new class of genetic pathways for cardiac sudden death and associated arrhythmias has been based on transcription factors that control conduction system lineages, including HF1b/SP4 and NKX2 [5].

High impact information on SP4

• Tissues were assayed with the monoclonal antibodies EP10 and SP4, which recognize synaptophysin, and the monoclonal antibodies SP6 and SP14, which detect syntaxin and synaptosomal-associated protein-25-kd immunoreactivities, respectively [6].
• Expression of human squamous cell differentiation marker, SPR1, in tracheobronchial epithelium depends on JUN and TRE motifs [7].
• Tracheobronchial epithelial (TBE) cells that normally do not express the squamous cell differentiation marker gene, SPR1, can be induced to produce it by 12-O-tetradecanoylphorbol-13-acetate (TPA) [7].
• The regulation of SPR1 gene expression by TPA occurs, in part, at the transcriptional level in primary human and monkey TBE cells [7].
• SPR-2 mRNA is expressed ubiquitously, whereas SPR-1 transcripts are abundant in the brain but barely detectable in other organs [8].

Biological context of SP4

• Human Sp4 transcription factor gene (SP4) maps to chromosome 7p15 [9].
• Several studies have demonstrated that SPR1 antibodies react with nuclear proteins and that SPR1 is expressed in cells before entering the G0 phase of the cell cycle [1].
• SPR expression can be regulated by transcriptional factors, by posttranscriptional factors, or by factors that affect SPR1 mRNA translation or protein turnover [1].
• The deduced amino acid sequence of G(0)SPR1 showed a high homology to the family of SPR1 from different species [10].
• Consistent with this phenotype, spr1 plants exhibited normal PI induction in response to oligosaccharide signals that are thought to play a role in the local wound response [11].

Anatomical context of SP4

• By day 10, labeled macrophages had large amounts of surface antigen and were in SP3 and SP4 [12].
• In our assay, two strains of M. fermentans were grown in SP4 glucose broth, mixed with fresh whole blood samples (n > 20), and incubated at 37 degrees C. The blood samples were then stained with a polyclonal antibody to M. fermentans, a monoclonal antibody to B-lymphocytes (CD19), and a monoclonal antibody to T-lymphocytes (CD3) [13].
• However, expression of SPR1 in nonsquamous tissues and cell lines indicates a function not associated with squamous differentiation [1].
• Although SPR1 is absent in normal mucociliary epithelium of the respiratory tract, epithelia that undergo squamous differentiation in response to vitamin-A deficiency or to injury owing to exposure to environmental toxicants express SPR1 [1].
• C355.1, and a human combinatorial antibody, SP4, we examined the ducts of these salivary glands for the presence of the characteristic aberrant staining pattern found in patients with PBC [3].

Associations of SP4 with chemical compounds

• Like Sp1, SPR-1 and SPR-2 contain glutamine and serine/threonine rich amino acid stretches [8].
• Other synthetic polyesters such as poly(trimethylene adipate) (SP3/6), poly(tetramethylene adipate) (SP4/6), and aliphatic-aromatic copolyesters from 1,4-butanediol, terephthalic acid, and adipic acid (BTA-copolymers) exhibit only very low anaerobic microbial susceptibility [14].
• We have developed specific and sensitive radioimmunoassays for progesterone in saliva (SP4) easily applicable in routine practice to assess ovarian function [15].
• Here, this question was addressed by characterizing a systemin-insensitive mutant (spr1) that was previously identified as a suppressor of prosystemin-mediated responses [11].
• In contrast to JA biosynthetic or JA signaling mutants that lack both local and systemic PI expression in response to wounding, spr1 plants were deficient mainly in the systemic response [11].

Other interactions of SP4

• SP1 had the lowest fluorescence per cell, and SP4 had the highest [12].
• Competitive inhibition of immunohistochemical staining using PDC-E2 specific human combinatorial antibodies SP1 and SP4 was performed using five of the above dodecapeptides [16].
• Immunohistochemistry for cyclin D1 was performed using the SP4 and the results were scored according to the Allred scoring system [17].
• The development of specific and sensitive electroimmunoassays for a recently identified high molecular weight alpha-2 mobile pregnancy-specific protein (pregnancy-associated plasma protein A, PAPP-A or SP4) is described [18].

Analytical, diagnostic and therapeutic context of SP4

• Using PCR, low levels of SPR1 mRNA were identified in a number of nondifferentiating cell lines and in nonsquamous tissues [10].

References