Genome mining for unknown-unknown natural products.

Genome mining of biosynthetic pathways with no identifiable core enzymes can lead to discovery of the so-called unknown (biosynthetic route)-unknown (molecular structure) natural products. Here we focused on a conserved fungal biosynthetic pathway that lacks a canonical core enzyme and used heterologous expression to identify the associated natural product, a highly modified cyclo-arginine-tyrosine dipeptide. Biochemical characterization of the pathway led to identification of a new arginine-containing cyclodipeptide synthase (RCDPS), which was previously annotated as a hypothetical protein and has no sequence homology to non-ribosomal peptide synthetase or bacterial cyclodipeptide synthase. RCDPS homologs are widely encoded in fungal genomes; other members of this family can synthesize diverse cyclo-arginine-Xaa dipeptides, and characterization of a cyclo-arginine-tryptophan RCDPS showed that the enzyme is aminoacyl-tRNA dependent. Further characterization of the biosynthetic pathway led to discovery of new compounds whose structures would not have been predicted without knowledge of RCDPS function.

PTBP1 controls intestinal epithelial regeneration through post-transcriptional regulation of gene expression.

The intestinal epithelial regeneration is driven by intestinal stem cells under homeostatic conditions. Differentiated intestinal epithelial cells, such as Paneth cells, are capable of acquiring multipotency and contributing to regeneration upon the loss of intestinal stem cells. Paneth cells also support intestinal stem cell survival and regeneration. We report here that depletion of an RNA-binding protein named polypyrimidine tract binding protein 1 (PTBP1) in mouse intestinal epithelial cells causes intestinal stem cell death and epithelial regeneration failure. Mechanistically, we show that PTBP1 inhibits neuronal-like splicing programs in intestinal crypt cells, which is critical for maintaining intestinal stem cell stemness. This function is achieved at least in part through promoting the non-productive splicing of its paralog PTBP2. Moreover, PTBP1 inhibits the expression of an AKT inhibitor PHLDA3 in Paneth cells and permits AKT activation, which presumably maintains Paneth cell plasticity and function in supporting intestinal stem cell niche. We show that PTBP1 directly binds to a CU-rich region in the 3' UTR of Phlda3, which we demonstrate to be critical for downregulating the mRNA and protein levels of Phlda3. Our results thus reveal the multifaceted in vivo regulation of intestinal epithelial regeneration by PTBP1 at the post-transcriptional level.

Report of the IDEOM Meeting Adjacent to the GRAPPA 2023 Annual Meeting.

The nonprofit organization International Dermatology Outcome Measures (IDEOM) is committed to improving the implementation of patient-centered outcome measures in dermatologic disease. At a conference adjacent to the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA) 2023 annual meeting, the IDEOM Psoriatic Disease Workgroup presented updates on recent efforts in outcome measure advancement. Dr. Alice Gottlieb presented the preliminary findings of a study within the Mount Sinai Health System that aims to determine how well the IDEOM musculoskeletal (MSK) symptom framework, which uses the Psoriasis Epidemiology Screening Tool (PEST) and the Psoriatic Arthritis Impact of Disease (PsAID) instruments, functions in clinical settings. Drs. Joseph Merola and Lourdes Perez-Chada updated attendees on the IDEOM MSK-Q, a 9-item patient-reported questionnaire designed to measure the intensity and impact of MSK symptoms on the quality of life in patients with psoriasis (PsO) with or without psoriatic arthritis (PsA). Dr. Vibeke Strand summarized the Outcome Measures in Rheumatology (OMERACT) 2023 conference sessions. Dr. April Armstrong discussed the preliminary findings of a multicentered study designed to validate the 7-item Dermatology Treatment Satisfaction Instrument (DermSat-7) among patients with PsO. She also introduced the Psoriasis and Psoriatic Arthritis Treatment Satisfaction Instrument, a tool that seeks to capture the level of patient satisfaction with current therapy for PsO and PsA. This report summarizes the developments discussed at the IDEOM PsO and PsA research workgroups during the GRAPPA 2023 annual meeting.

Engineered biosynthesis of plant heteroyohimbine and corynantheine alkaloids in Saccharomyces cerevisiae.

Monoterpene indole alkaloids (MIAs) are a class of natural products comprised of thousands of structurally unique bioactive compounds with significant therapeutic values. Due to difficulties associated with isolation from native plant species and organic synthesis of these structurally complex molecules, microbial production of MIAs using engineered hosts are highly desired. In this work, we report the engineering of fully integrated Saccharomyces cerevisiae strains that allow de novo access to strictosidine, the universal precursor to thousands of MIAs at 30-40 mg/L. The optimization efforts were based on a previously reported yeast strain that is engineered to produce high titers of the monoterpene precursor geraniol through compartmentalization of mevalonate pathway in the mitochondria. Our approaches here included the use of CRISPR-dCas9 interference to identify mitochondria diphosphate transporters that negatively impact the titer of the monoterpene, followed by genetic inactivation; the overexpression of transcriptional regulators that increase cellular respiration and mitochondria biogenesis. Strain construction included the strategic integration of genes encoding both MIA biosynthetic and accessory enzymes into the genome under a variety of constitutive and inducible promoters. Following successful de novo production of strictosidine, complex alkaloids belonging to heteroyohimbine and corynantheine families were reconstituted in the host with introduction of additional downstream enzymes. We demonstrate that the serpentine/alstonine pair can be produced at ∼5 mg/L titer, while corynantheidine, the precursor to mitragynine can be produced at ∼1 mg/L titer. Feeding of halogenated tryptamine led to the biosynthesis of analogs of alkaloids in both families. Collectively, our yeast strain represents an excellent starting point to further engineer biosynthetic bottlenecks in this pathway and to access additional MIAs and analogs through microbial fermentation. ONE SENTENCE SUMMARY: An Saccharomyces cerevisiae-based microbial platform was developed for the biosynthesis of monoterpene indole alkaloids, including the universal precursor strictosidine and further modified heteroyohimbine and corynantheidine alkaloids.

The Hidden Costs of Psoriasis: A Population-Based Study Evaluating How Psoriasis Severity Impacts Work Absenteeism.

BACKGROUND: Psoriasis patients experience physical and emotional burdens, which may lead to work-related productivity loss. This loss carries professional and financial repercussions. It is unknown whether the extent of psoriasis affects work absenteeism. OBJECTIVE: This study aims to compare work absenteeism between employed adults with mild versus moderate-to-severe psoriasis. METHODS: A national, cross-sectional study using the 2009 to 2019 Medical Expenditure Panel Survey evaluated 5,209,956 (weighted) adults aged ≥ 22 years. Work absenteeism was compared between adults with mild (4,521,687 weighted) and moderate-to-severe psoriasis (688,269 weighted). RESULTS: Work absenteeism, as measured by the average number of episodes per year that someone was absent from work for at least a half day, was significantly higher in patients with moderate-to-severe psoriasis than in patients with mild disease (4.4 episodes vs 2.8 episodes, P=0.002). Multivariable logistic regression models showed moderate-to-severe patients were 2.68 times more likely (95% CI:1.72-4.21; P<0.001) to take a half-day or more off from work than those with mild disease after adjusting for age, sex, race, ethnicity, poverty, cognitive limitations, insurance, education, and comorbidities. CONCLUSION: Disease severity directly impacts work absenteeism in psoriasis patients. Early diagnosis and treatment with appropriate therapies are needed to reduce disease severity and limit economic loss and professional ramifications associated with psoriasis. J Drugs Dermatol. 2024;23(8):640-644.  doi:10.36849/JDD.7550.

Tips, Trends, and Truths: A Study of Psoriasis Treatment Content on TikTok.

INTRODUCTION: With more than two billion downloads since its launch, TikTok is the fastest-growing video-sharing platform in the world. Many people turn to TikTok for dermatologic medical information. However, there is limited data about psoriasis and psoriasis treatment content on this social media platform. OBJECTIVE: To compare the viewer engagement, content quality, and viewer experience of psoriasis treatment TikTok videos between physicians and non-physicians. METHODS: We searched the terms "psoriasis" and "psoriasis treatment" on TikTok. Video characteristics were collected. Content quality was evaluated using DISCERN. Viewer experience was assessed using the AVA. RESULTS: Viewer engagement did not significantly differ between physicians and non-physician content creators (0.033 plus/minus 0.005 vs 0.047 plus/minus 0.001, P=0.066). Compared to non-physicians, physicians created videos of higher quality (DISCERN: 1.76 plus/minus 0.058 vs 1.44 plus/minus 0.032, P<0.001) and of greater viewer experience (AVA: 2.55 plus/minus 0.183 vs 1.96 plus/minus 0.081, P=0.001). However, there is room for improvement in terms of creating videos of higher quality by both physicians and non-physicians. CONCLUSION: TikTok can be a powerful tool to promote health literacy and dispel misinformation. Dermatologists may consider focusing their efforts on creating comprehensive educational content and incorporating trending features to reach a wider audience. J Drugs Dermatol. 2024;23(2): doi:10.36849/JDD.7050e.

Complementary and Alternative Medicine for Hidradenitis Suppurativa Discussed on TikTok: A Cross-Sectional Analysis.

BACKGROUND: Hidradenitis suppurativa (HS) is a painful, chronic inflammatory skin disease that negatively affects patient quality of life, and conventional treatments are variably effective. As a result, patients often turn to complementary and alternative medicine (CAM) for pain relief. Social media enables HS patients to share treatment recommendations. TikTok is a popular social media platform, but little is known about the HS treatments discussed in TikTok videos.  Objective: To evaluate the content and quality of information on TikTok regarding CAM HS therapies.  Methods: A cross-sectional analysis was conducted by performing a search in TikTok using the terms #hidradenitissuppurativa, #hswarrior, #naturalremedy, #complementarymedicine, #alternativemedicine, and #HStreatment. Two independent reviewers evaluated video quality using the DISCERN and AVA instruments. Linear regressions compared the engagement, DISCERN, and AVA scores among different uploader types. RESULTS: In total, 91 TikTok videos were analyzed. Videos were uploaded by non-physicians (82.4), dermatologists (6.6%), and private companies (11.0%). The average DISCERN and AVA scores were 36.2 and 1.6, respectively (poor quality). Common CAM therapies were natural salves, turmeric, Epsom salts, elimination diets, and zinc supplements. Physician-uploaded videos were of significantly higher quality than videos by other uploader types, with an average DISCERN and AVA score of 44.3 (P<0.009) and 2.6 (P<0.001), respectively (fair quality). CONCLUSION: TikTok videos were poor quality (low DISCERN and AVA scores); physician-uploaded videos were fair quality. Dermatologists can improve video quality by adequately discussing the supporting evidence, mechanisms of action, and remaining questions for HS treatments.  J Drugs Dermatol. 2024;23(3):e93-96. doi:10.36849/JDD.7738e.

Teledermatology Use in the Elderly: An Analysis of Teledermatology Utilization Patterns Across Age Groups.

Introduction: Telehealth is an emerging tool used to improve access to care for patients. However, there is a lack of literature comparing the use of telehealth between patients of different age groups in dermatology. Our study aims to determine whether differences exist in teledermatology usage between elderly and younger dermatology patients. Methods: We conducted a cross-sectional study using the 2020-2021 Medical Expenditure Panel Survey. Our study population included a weighted total of 150,290,604 patients: Of these, 16.35% were young adults (18-44 years old), 26.32% were midlife adults (45-64 years old), and 57.33% were elderly (65+ years old). Results: Our results showed that elderly patients had significantly lower rates of teledermatology use than young adults (odds ratio [OR] = 0.184, (confidence interval [CI]: 0.081-0.421)), p < 0.000) and midlife adults (OR = 0.193, [CI: 0.091-0.406], p < 0.000). Midlife adults had similar rates of telehealth use when compared with young adults (OR = 1.044, [CI: 0.508-2.145], p = 0.907). Our results were adjusted for sex, race, ethnicity, insurance type, education level, income, travel time, and medical comorbidities. Discussion: We found that elderly patients seeking dermatology care are less likely to use telehealth than younger dermatology patients. Our results demonstrate that barriers to telehealth use for the elderly may be more prohibitive than expected. Understanding these differences in teledermatology use is essential for improving teledermatology delivery across all age groups.

Shared decision-making and satisfaction with care in patients with psoriasis: A population-based study in the United States.

BACKGROUND: Shared decision-making (SDM) is a critical component of the patient-physician relationship. Although SDM has been reported to improve patient knowledge in other fields, it is still relatively unknown in dermatology. OBJECTIVE: To determine the association between SDM and satisfaction with care among patients with psoriasis. METHODS: Cross-sectional study using data from the 2014 to 2017 and 2019 Medical Expenditure Panel Survey. RESULTS: A weighted total of 3,715,027 patients with psoriasis were identified. The average SDM score was 3.6 (of 4), and the average satisfaction with care score was 8.6 (of 10). Approximately 42% of the cohort reported having a high SDM (score, ≥3.9). Patients who had high SDM had, on average, 85% higher satisfaction with care (P < .001) after adjusting for covariates. LIMITATIONS: The results of our study should be interpreted within the context of the Medical Expenditure Panel Survey database. The ability to measure SDM was limited by the 7 items from Medical Expenditure Panel Survey, which may not fully capture active participation in shared decision-making. CONCLUSION: A majority of patients with psoriasis are not participating in highly SDM. It is important to construct a framework for carrying out SDM efficiently to enhance physician-patient communication and improve patient outcomes.

Shared decision-making and satisfaction with care: a population-based study in patients with acne with skin of colour in the USA.

Little is known about differences in shared decision-making and patient satisfaction with acne care among different ethnicities and races. We conducted a cross-sectional study to determine differences between patients with acne who are White and those with skin of colour (SOC), i.e. (i) engagement in shared decision-making, and (ii) patient satisfaction with care, using the 2009-2017 and 2019 Medical Panel Expenditure Survey. Patients with acne with SOC were nearly two times more likely to engage in high shared decision-making compared with White patients [adjusted odds ratio 1.80, 95% confidence interval (CI) 1.30-2.51, P < 0.001]. Patients with SOC with acne reported lower satisfaction with care compared with White patients (ß = -0.38, 95% CI -0.69 to -0.06, P = 0.02). Patients with SOC who had acne reported higher levels of shared decision-making than White patients. However, compared with the White patients, patients with SOC report lower satisfaction with their care. There may be other factors contributing to lower satisfaction with care in patients with SOC who have acne.

No Racial Differences Found in Access to Biologics: A Population-Based Study of Psoriasis Patients in the United States.

BACKGROUND: Conflicting evidence exists regarding the role of race in access to biologics for patients with psoriasis. OBJECTIVE: To compare biologic use among adult and pediatric United States psoriasis patients of different racial backgrounds. METHODS: Population-based study of US psoriasis patients using the 2003 to 2018 Medical Expenditure Panel Survey (MEPS). RESULTS: Among 31,525,500 adults and children with psoriasis (weighted), 3,026,578 (9.6%) were on biologics. Among psoriasis patients, 27,464,864 (87.1%) self-identified as white, 2,033,802 (6.5%) self-identified as Black, 1,173,435 (3.7%) self-identified as Asian or Pacific Islander, and 853,399 (2.7%) self-identified as other races. Among those on biologics, 2,778,239 (91.8%) self-identified as white, 84,971 (2.8%) identified as Black, 89,452 (3.0%) self-identified as Asian or Pacific Islander, and 73,917 (2.4%) self-identified as other races. Multivariate logistic regression revealed no significant differences in biologic access between whites and non-whites after adjusting for sociodemographic factors including insurance status (OR for Blacks: 0.347 [0.118, 1.021], P=0.055; OR for Asians: 0.616 [0.240, 1.579], P=0.311; OR for other races: 0.850 [0.216, 3.336], P=0.814. CONCLUSION: The results of this study suggest that race alone is not independently associated with access to biologics among adult US psoriasis patients. Additional studies are necessary to evaluate factors independently associated with biologics access among adults and children with psoriasis in the US. J Drugs Dermatol. 2023;22(8):835-837. doi:10.36849/JDD.7134 Reddy R, Khan S, Yee D, et al. No racial differences found in access to biologics: a population-based study of psoriasis patients in the United States. .

Evaluating Sentiment, Engagement, and Perception of Biologics Among Patients with Psoriasis and Psoriatic Arthritis on Reddit.

BACKGROUND: Limited analyses of social media content among psoriasis (PsO) and psoriatic arthritis (PsA) patients exist. These patients may turn to social media to gain insight into treatments such as biologics. OBJECTIVES: This study aims to analyze the content, sentiment, and engagement of social media posts regarding biologics for PsO and PsA. METHODS: Posts and comments discussing biologics were extracted from publicly accessible PsO and PsA Reddit groups. Posts were assigned higher (HOT) and lower order (LOT) themes, sentiments, and engagement scores. RESULTS: Of 1141 posts extracted, 705 posts were classified under the HOT general/efficacy. Twelve lower order themes (LOTs) were identified: general advice/experience (10.2%), symptoms improved (36.6%), switching biologics (10.5%), and time to results (13.4%). 61.3% of content was of positive sentiment, 24.0% was neutral, and 14.7% was of negative sentiment. The mean sentiment score, defined as the average of all posts' sentiment scores (where negative=-1, neutral=0, and positive=1), was overall positive at 0.47, 95% CI [.41-.52]. Mean sentiment scores between LOTs were significantly different (P<0.001). Information regarding biologics on Reddit is mostly positive; however, there remains a significant number of users expressing dissatisfaction with their efficacy or with biologics in general. Many users sought anecdotal advice. CONCLUSION: These findings can help guide educational efforts to anticipate concerns and appease hesitancy regarding biologics and their efficacy. J Drugs Dermatol. 2023;22(3):306-309. doi:10.36849/JDD.7124.

Differences in accessing dermatology offices, primary care offices, and emergency departments between Hispanics and Non-Hispanic White Patients.

How Hispanic patients access dermatologic care for skin diseases is unknown. This study aims to determine if differences exist in accessing the emergency department (ED), primary care, and outpatient dermatologic offices for skin diseases between Hispanic and non-Hispanic White patients. This cross-sectional study used nationally representative data from the Medical Panel Expenditure Survey (MEPS) from 2016-2019. A total of 109,337,668 (weighted) patients with any skin disease diagnosed at an ED, primary care, or dermatology visit were identified. Hispanics comprised 13.0% and non-Hispanic Whites comprised 68.8% of this subpopulation. Overall, 94.1% of Hispanic patients attended a primary care visit for their skin complaint, 5.8% saw a dermatologist, and 0.1% attended an ED visit. Compared to non-Hispanic Whites, Hispanics were more likely to attend a primary care visit (aOR 1.865; 95%CI, 1.640-2.122) and less likely to attend an outpatient dermatology visit (aOR 0.536; 95%CI, 0.471-0.610), after adjusting for insurance status, education, income, sex, age, and comorbidities. Our study suggests that, compared to non-Hispanic Whites, Hispanic patients access primary care more frequently and outpatient dermatologic offices less frequently for their skin conditions. Language barriers, less familiarity with the healthcare system, and lack of adequate health insurance may play roles in this observation.

Structure of the Repurposed Fungal Terpene Cyclase FlvF Implicated in the C-N Bond-Forming Reaction of Flavunoidine Biosynthesis.

The fungal species Aspergillus flavus produces an alkaloid terpenoid, flavunoidine, through a hybrid biosynthetic pathway combining both terpene cyclase and nonribosomal peptide synthetase enzymes. Flavunoidine consists of a tetracyclic, oxygenated sesquiterpene core decorated with dimethyl cadaverine and 5,5-dimethyl-l-pipecolate moieties. Unique to the flavunoidine biosynthetic pathway is FlvF, a putative enzyme implicated in stereospecific C-N bond formation as dimethyl cadaverine is linked to the sesquiterpene core to generate pre-flavunoidine. Here, we report the 2.6 Å resolution crystal structure of FlvF, which adopts the α-helical fold of a class I terpene synthase. However, FlvF is not a terpene synthase, as indicated by its lack of enzymatic activity with farnesyl diphosphate and its lack of signature metal ion binding motifs that would coordinate to catalytic Mg2+ ions. Thus, FlvF is the first example of a protein that adopts a terpene synthase fold but is not a terpene synthase. Two Bis-Tris molecules bind in the active site of FlvF, and the binding of these ligands guided the docking of pre-flavunoidine to generate a model of the enzyme-product complex. Phylogenetic analysis of FlvF and related fungal homologues reveals conservation of residues that interact with the tetracyclic sesquiterpene in this model, but less conservation of residues interacting with the pendant amino moiety. This may hint toward the possibility that alternative amino substrates can be linked to a common sesquiterpene core by FlvF homologues to generate flavunoidine congeners, such as the phospholipase C inhibitor hispidospermidin.

"I'm Off My Meds": Public Perception of Interactions Between SARS-CoV-2 Vaccines and Anti-Psoriatic Treatments Online.

IMPORTANCE: Psoriasis patients may seek information about the SARS-CoV-2 vaccine and their diagnosis from social media platforms. Analyses of social media interactions may help guide dermatologists’ educational efforts during this pandemic. OBJECTIVES: This study analyzed the content and sentiment of online social media posts about the medication interaction between SARS-CoV-2 vaccines and anti-psoriatic therapies among psoriasis patients. DESIGN: Publicly accessible Facebook and Reddit groups regarding psoriasis and psoriatic arthritis were identified. Posts uploaded between March 1, 2021, and July 31, 2021, with information about the SARS-CoV-2 vaccine and psoriasis and psoriatic arthritis, were extracted. Themes, sentiment scores, and engagement scores were assigned to each post. RESULTS: 477 posts contained content pertaining to the vaccine and psoriatic medications. 19 (4%) of the posts contain negative sentiment, 232 (48.6%) contain neutral sentiment, and 226 (47.4%) contain positive sentiment. Several themes emerged from this study. A majority of posts (32.5%) contained concerns about holding or stopping medications prior to obtaining the vaccine. Other common concerns included fear of negative reaction (21.8%) and uncertainty about the ability to generate an efficient immune response to the vaccine while on anti-psoriatic medications (19.9%). CONCLUSIONS AND RELEVANCE: Concerns identified by our content analysis should be incorporated into education efforts to address the reasons for vaccine hesitancy among patients with psoriatic diseases. These patient concerns can also help guide our strategy for implementing evidence-based recommendations on COVID-19 vaccination. J Drugs Dermatol. 2022;21(8):901-905. doi:10.36849/JDD.6853.

Biologics to breast milk: A cross-sectional study of popular eczema treatment content on TikTok.

We conducted a cross-sectional study to compare viewer engagement, content quality and viewer experience of eczema related medical content on TikTok between health care professionals and non-health care professionals. Compared to non-health care professionals, health care professionals created videos of higher quality and superior viewing experience. Viewer engagement did not differ significantly between videos made by health care professionals and non-health care professionals. Overall, content creators should focus on producing comprehensive, evidence-based videos.

Genome Mining of Alkaloidal Terpenoids from a Hybrid Terpene and Nonribosomal Peptide Biosynthetic Pathway.

Biosynthetic pathways containing multiple core enzymes have potential to produce structurally complex natural products. Here we mined a fungal gene cluster that contains two predicted terpene cyclases (TCs) and a nonribosomal peptide synthetase (NRPS). We showed the flv pathway produces flavunoidine 1, an alkaloidal terpenoid. The core of 1 is a tetracyclic, cage-like, and oxygenated sesquiterpene that is connected to dimethylcadaverine via a C-N bond and is acylated with 5,5-dimethyl-l-pipecolate. The roles of all flv enzymes are established on the basis of metabolite analysis from heterologous expression.

Engineered mitochondrial production of monoterpenes in Saccharomyces cerevisiae.

Monoterpene indole alkaloids (MIAs) from plants encompass a broad class of structurally complex and medicinally valuable natural products. MIAs are biologically derived from the universal precursor strictosidine. Although the strictosidine biosynthetic pathway has been identified and reconstituted, extensive work is required to optimize production of strictosidine and its precursors in yeast. In this study, we engineered a fully integrated and plasmid-free yeast strain with enhanced production of the monoterpene precursor geraniol. The geraniol biosynthetic pathway was targeted to the mitochondria to protect the GPP pool from consumption by the cytosolic ergosterol pathway. The mitochondrial geraniol producer showed a 6-fold increase in geraniol production compared to cytosolic producing strains. We further engineered the monoterpene-producing strain to synthesize the next intermediates in the strictosidine pathway: 8-hydroxygeraniol and nepetalactol. Integration of geraniol hydroxylase (G8H) from Catharanthus roseus led to essentially quantitative conversion of geraniol to 8-hydroxygeraniol at a titer of 227 mg/L in a fed-batch fermentation. Further introduction of geraniol oxidoreductase (GOR) and iridoid synthase (ISY) from C. roseus and tuning of the relative expression levels resulted in the first de novo nepetalactol production. The strategies developed in this work can facilitate future strain engineering for yeast production of later intermediates in the strictosidine biosynthetic pathway.