SEPT14 Antibody

What is SEPT14 and what biological systems express this protein?

SEPT14 is a member of the septin family of GTPases involved in various cellular processes. It is expressed in both reproductive and nervous system tissues. In the brain, SEPT14 mRNA has been detected in the dentate gyrus (DG), hippocampal CA1–CA3 regions, and cerebral cortex . Single-cell RNA-sequencing analysis has shown that the anterolateral motor cortex and hippocampal region express low levels of Sept14 . In the male reproductive system, SEPT14 is mainly localized at the sperm head and tail, with expression levels in testicular tissues being lower in infertile men with conditions like hypospermatogenesis compared to fertile men .

What are the key characteristics of commercially available SEPT14 antibodies?

The antibody is supplied at 1 mg/ml concentration in PBS (without Mg²⁺ and Ca²⁺), pH 7.4, 150 mM NaCl, 0.02% sodium azide, 50% glycerol .

What is the subcellular localization of SEPT14 during sperm development?

During sperm development, SEPT14 displays a dynamic localization pattern. Initially, it is predominantly localized to the perinuclear rim and manchette structure (a transitional structure for sperm head shaping consisting of tubulin and actin) in early elongating spermatids . As sperm head formation progresses, SEPT14 gradually becomes concentrated in the narrowing manchette . This changing pattern suggests SEPT14 plays an important role in the mechanical process of sperm head shaping during spermiogenesis .

What protein interactions does SEPT14 participate in during cellular processes?

SEPT14 interacts with several proteins during cellular processes, particularly in sperm development. Using co-immunoprecipitation followed by mass spectrometry analysis, researchers have identified SEPT14 interactors that can be classified into four main categories :

SEPT14 specifically interacts with ACTN4, co-localizing with it in the perinuclear and manchette regions of the sperm head in early elongating spermatids . This interaction appears critical, as mutations in SEPT14 disturb the normal localization pattern of ACTN4 .

What experimental approaches can be used to study SEPT14-protein interactions?

Multiple complementary techniques have been successfully employed to investigate SEPT14 protein interactions:

• Co-immunoprecipitation (co-IP): Researchers have used FLAG-tagged SEPT14 constructs transfected into male germ cell lines (NT2D1) followed by immunoprecipitation with FLAG antibodies to isolate SEPT14 protein complexes .

• Mass Spectrometry Analysis: Immunoprecipitated samples can be processed through:

  • Reduction with dithiothreitol

  • S-alkylation with iodoacetamide

  • Enzymatic digestion with Lys-C and trypsin

  • Desalting with SDB-XC StageTip followed by SCX StageTip

  • Analysis via liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS)

• Protein Interaction Network Analysis: Data from experimental results can be analyzed using STRING bioinformatics tools to visualize and understand interaction networks .

• Immunofluorescence Co-localization: This technique helps visualize the spatial relationship between SEPT14 and its interacting partners in cellular contexts .

How can researchers generate and validate SEPT14 knockout models?

SEPT14 knockout models can be effectively generated using CRISPR/Cas9 technology as demonstrated in recent research . Validation of the knockout should include:

• Genotypic confirmation: PCR analysis to verify deletion of the SEPT14 gene .

• Transcript verification: RT-PCR to confirm absence of SEPT14 expression in relevant tissues including hippocampus, cerebellum, prefrontal cortex, and testes .

• Tissue-specific expression analysis: BaseScope in situ hybridization can be used to examine regional expression patterns of Sept14 mRNA in wild-type versus knockout tissues .

• Physiological assessment: Evaluation of physical development parameters (body weight, brain weight, brain/body weight ratio) and fertility to determine if SEPT14 is essential for development, viability, or reproductive function .

What phenotypic effects result from SEPT14 mutations or deletion?

Mutations and deletion of SEPT14 lead to distinct phenotypic effects:

SEPT14 Mutations in Humans:

• Two specific mutations have been identified in teratozoospermia donors: SEPT14 A123T (p.Ala123Thr) and SEPT14 I333T (p.Ile333Thr) .

• Sperm from donors with these mutations exhibit a high percentage of head defects (90 ± 4%) and elevated levels of nuclear damage .

• Mutant SEPT14 proteins disrupt the polymerization ability and co-localization of F-actin filaments in vitro .

• SEPT14 mutations have been associated with a reduced risk of Parkinson's disease, suggesting neurological implications .

SEPT14 Knockout in Mice:

• SEPT14 knockout mice are viable and fertile with no obvious health problems observed up to 32 weeks of age .

• Male SEPT14 knockout mice show enhanced latency to enter the dark compartment in inhibitory avoidance tests, suggesting elevated aversion-related memory .

• This behavioral effect shows sexual dimorphism, as it was not observed in female knockout mice .

• Minor physical differences include slightly increased body weight and decreased brain/body weight ratio in 8-week-old male SEPT14 knockout mice .

How does mutated SEPT14 affect cellular mechanisms in sperm development?

SEPT14 mutations disrupt normal sperm head formation through mechanism involving ACTN4 and the actin cytoskeleton. When SEPT14 is mutated:

• The normal interaction between SEPT14 and ACTN4 (an actin-holding protein) is disturbed .

• This disruption affects ACTN4's proper localization in developing sperm cells .

• Consequently, actin filament organization and polymerization are compromised .

• The manchette structure, critical for sperm head shaping, fails to function properly .

• These cascading effects result in severely malformed sperm heads and DNA fragmentation .

This pathway demonstrates how a single protein mutation can disrupt complex cytoskeletal interactions necessary for proper cellular morphogenesis.

What are promising areas for further investigation of SEPT14 function?

Given the current research findings, several avenues for future investigation appear promising:

• Neurological functions: The association between SEPT14 mutations and reduced Parkinson's disease risk, along with the behavioral changes observed in knockout mice, suggest unexplored neurological roles for this protein .

• Sex-specific effects: The sexual dimorphism observed in behavioral phenotypes of knockout mice warrants investigation into potential hormone-dependent or sex-specific functions of SEPT14 .

• Therapeutic applications: Understanding how SEPT14 mutations affect sperm development could lead to novel approaches for treating certain forms of male infertility .

• Developmental roles: Further characterization of SEPT14 expression during embryonic and postnatal development could reveal additional functions beyond those currently identified in mature tissues .

• Protein interaction network expansion: More comprehensive mapping of SEPT14 interaction partners in different tissues could uncover tissue-specific functions and regulatory mechanisms .